RIP

10:19 AM PDT -- Law enforcement sources tell us ... Mitchell was out in his boat along the Belle River ... when he "fell." Witnesses say he appeared to have been suffering from a seizure.

We're told another person on the boat returned the vessel to the dock and called 911. Emergency personnel responded to the scene and transported Mitchell to a nearby hospital ... but it was too late.

12:15 PM PDT -- A rep for the History Channel tells us, "We are extremely saddened to report that our friend and beloved member of the Swamp People family, Mitchell Guist, has passed away earlier today. Mitchell passed on the swamp, doing what he love."

4:11 PM PDT -- The 911 call, placed moments after Mitchell Guist fell, was just released to a local news station. According to the caller, Mitchell had a seizure then went into cardiac arrest.

Mitchell Guist -- one of the bearded alligator-hunting brothers featured on the reality show "Swamp People" -- has died.

According to WBRZ.com, Mitchell was discovered at 9 AM in St. Martin Parish, Louisiana.

Law enforcement sources tell us ... someone tried to perform CPR on Guist ... but attempts to resuscitate the reality star were unsuccessful.

Sources close to Mitchell tell us ... Guist had recently fallen ill ... but the nature of his illness is still unclear.

Story developing ...

The late Carroll Shelby didn't just invent one of the coolest sports cars ever ... he also INVENTED THE WORLD CHILI COOKOFF ... and TMZ has learned the chili community is planning a memorial to honor their spicy savory king.

TMZ spoke with Ed Blair -- President of the Chili Appreciation Society International -- who tells us Shelby will be honored at the Terlingua International Chili Championship (think Super Bowl of chili).

According to Blair, Shelby's image will be featured on a memorial board ... along with other chili legends who died in the past year.

Legendary car designer and racing driver Carroll Shelby has died.

Shelby is known for introducing the Shelby AC Cobra to the United States in the 1960s -- combining an English sports car chassis with an American Mustang engine.

A rep for Shelby's company Carroll Shelby International says Shelby died today at a Dallas hospital. He had received a heart transplant in 1990 and a kidney transplant in 1996.

As a driver -- Shelby first gained fame by winning France's arduous 24 Hours of Le Mans in 1959.

World-renowned hair stylist and fashion icon Vidal Sassoon has died.

According to reports, Sassoon passed away today from an unspecified illness at his home on Mulholland Drive in Hollywood. His family was by his side.

Vidal is credited with creating the famous haircut called the "bob."

Vidal was reportedly diagnosed with leukemia in 2009. It's unclear what role the cancer played in his death.

The hair icon was married four times -- most recently to Rhonda Sassoon in 1992, who stayed with him until his death. He is also survived by three children. Vidal was 84.

Vidal seemed pretty healthy right up until the end -- in fact, we spoke to him just last week ... and he gave us some pretty useful hair tips.

It's a terrible day for terrible creatures ... 'cause the man who wrote the children's classic, "Where the Wild Things Are" has died.

Maurice Sendak -- who not only wrote the book but ALSO drew the iconic "Wild Things" images -- passed away early this morning at a hospital in Connecticut after suffering a stroke on Friday.

"Where the Wild Things Are" was first published in 1963 ... and was adapted into a major motion picture in 2009 ... the same year President Obama read the book to children at the White House Easter Egg Roll.

Junior Seau was honored today when more than 1,000 people "paddled out" in the ocean to pay their respects to the NFL legend.

The water-based memorial took place in Oceanside, CA this afternoon -- directly in front of his beachfront home -- and allowed friends, neighbors and locals to mourn the superstar together. Surfers were heard chanting his name and jersey number as they gathered in the ocean.

Seau was known to be an avid surfer.

Seau died Wednesday from a self-inflicted gun shot wound to the chest. He was 43.

George Lindsey -- who appeared on such classic TV shows as "The Andy Griffith Show," "Gunsmoke" and "Hee Haw" -- died Sunday morning after an extended illness. He was 83.

Lindsey -- who grew up in Jasper, Alabama -- will be buried there, reports WSFA in Tennessee ... but no plans have been made yet.

Lindsey was probably best known for playing Goober on "The Andy Griffith Show." He got the part after originally auditioning for the role of Gomer Pyle, but lost out to Jim Nabors.

11:30 AM PT -- MCA's publicist just released a statement, writing, "It is with great sadness that we confirm that musician, rapper, activist and director Adam 'MCA' Yauch ... passed away in his native New York City this morning after a near-three-year battle with cancer. He was 47 years old."

1:00 PM PT -- A rep for the Dalai Lama -- of whom MCA was a huge supporter -- tells TMZ, "Adam had helped us raise awareness on the plight of the Tibetan people by organizing various freedom Tibet concerts and he will be remembered by his holiness and the Tibetan people."

Adam met several times with the Dalai Lama while he was sick -- most recently last July, when the Dalai Lama blessed him.

"Beastie Boys" rapper MCA -- real name Adam Yauch -- has died.

In 2009, MCA announced he was being treated for a cancerous parotid gland and a lymph node (below). He has since undergone surgery and radiation therapy.

Russell Simmons' website GlobalGrind.com first reported the death. We have spoken to people independently connected to the rapper who also say he is dead.

MCA co-founded Beastie Boys in 1979 with Mike D, and Ad Rock ... and went on to churn out some of the most iconic albums in hip-hop ... including License to Ill, Paul's Boutique, Check Your Head and Ill Communication.

The group has won multiple Grammys and were inducted into the Rock and Roll Hall of Fame earlier this year.

The Beastie Boys haven't performed live since summer 2009 -- and during one of their last ever performances at Bonnaroo that June, MCA appeared noticeably less energetic than his group mates.

MCA recently became a vegan at the recommendation of his Tibetan doctors.

The Beastie Boys' most recent music video was released last year for the song "Make Some Noise" -- and it stars a laundry list of A-listers, including Rashida Jones, Will Arnett, Rainn Wilson, Amy Poehler, Steve Buscemi, Kirsten Dunst, Zach Galifianakis, Orlando Bloom, Will Ferrell, John C. Reilly, and Jack Black.

Yauch is survived by his wife and daughter. He was 47.

Junior Seau's former teammate broke down in tears, live on the radio, moments after hearing about his death -- and wished he could have done something to save his friend.

Marcellus Wiley played with Seau as a San Diego Charger in 2001 and 2002 -- and now co-hosts the Max and Marcellus show on 710 ESPN in LA.

Marcellus was on the air today when TMZ broke the news about Seau's death -- and immediately got emotional sharing memories of his teammate.

4:09 PM PDT -- Law enforcement tells us ... investigators discovered a revolver at the scene. It's unclear who the gun belongs to.

1:52 PM PDT -- The Oceanside PD tells us ... Seau's girlfriend was at the home this morning and saw Seau alive ... before she left to the gym at 7:45 AM.

We're told when she returned ... she claims she discovered Seau bleeding from his chest and immediately called 911.

NFL legend Junior Seau was found dead at his Oceanside, CA home this morning from a self-inflicted gunshot wound to the chest -- law enforcement sources tell TMZ.

Oceanside Police Chief Frank McCoy just spoke outside Seau's San Diego house, claiming Seau's body was initially discovered by Seau's girlfriend.

A 911 call was placed around 10AM this morning -- authorities responded to the scene, and found Seau's unconscious body inside a bedroom with a gunshot wound to the chest.

Paramedics attempted to revive Seau, but life-saving efforts were unsuccessful. He was pronounced dead on the scene. His body has just been removed from the house and is currently being transported to the Medical Examiner's office in a white van.

McCoy says investigators recovered a handgun in the bedroom -- and the case is currently being investigated as a suicide.

A law enforcement official tells TMZ ... no suicide note has been discovered at the scene.

Seau's mother also spoke briefly -- and she was hysterical, crying to God, "Take me. Leave my son alone!"

Seau was 43-years-old. He is survived by 4 children and an ex-wife.

We're told Seau sent text messages to his ex-wife and kids yesterday saying, "Love you." They all responded, but didn't suspect anything was wrong. We're told he last saw his kids 3 weeks ago.

Sources close to Seau tell us family members didn't notice any signs of depression in recent weeks.

The fact Seau chose to shoot himself in the chest seems like a premeditated decision -- considering several NFL players have recently killed themselves in a similar fashion in order to preserve their brains for research purposes ... in the wake of new studies which appear to connect football-related concussions to suicidal behavior.

Seau was a beast in the NFL -- skyrocketing to fame thanks to his explosive play with the San Diego Chargers, Miami Dolphins and New England Patriots. The USC standout was selected in the first round of the NFL draft in 1990 and played in the league for 20 years.

Seau was involved in a car accident back in 2010 when he drove his SUV off a cliff in Carlsbad, CA hours after he was arrested for allegedly attacking his girlfriend. Seau later said he was not trying to kill himself ... insisting he had fallen asleep at the wheel.

The San Diego Chargers released a statement, claiming, "Everyone at the Chargers is in complete shock and disbelief right now...We ask everyone to stop what they're doing and send their prayers to Junior and his family."

The New England Patriots also released a statement, claiming, "This is a sad day for the entire Patriots organization, our coaches and his many Patriots teammates. Our heartfelt thoughts and prayers go out to his family and his many friends who will mourn this loss.”

Seau is the 8th member of the 1994 San Diego Chargers team to die before the age of 45 ... joining linebacker David Griggs, running back Rodney Culver, linebacker Doug Miller, center Curtis Whitley, defensive end Chris Mims, defensive tackle Shawn Lee and linebacker Lew Bush.

Junior Seau is the latest of several former NFL players to commit suicide -- and all the deaths might be linked ... through brain-related injuries sustained during the players' football careers.

Most recently, 62-year-old former Atlanta Falcons player Ray Easterling (center) shot himself last month in his Virginia home. His wife claims the former safety developed symptoms of dementia after his football career.

Easterling filed a federal lawsuit in Philly against the NFL in 2011 over its handling of concussion-related football injuries -- claiming the league intentionally concealed links between the injuries and the game.

Dozens and dozens of similar concussion-related lawsuits have also been filed against the NFL -- but the league insists the allegations are without merit.

50-year-old former Chicago Bears player Dave Duerson (right) was found dead in his Florida home last year from a self-inflicted gunshot wound to the chest.

Before his death, he texted his family asking for his brain to be used for research (hence why he shot himself in the chest). Months later, researcher neurologists at Boston University confirmed Duerson had suffered from a neurodegenerative disease linked to concussions.

It's possible Junior Seau shot himself in the chest for the same reason.

Terrell Owens had TWO near-death encounters involving pills -- most recently on October 6th, when his assistant called 911 claiming the NFL star had OD'd. T.O. nearly died back in 2006 too, after downing 36 Vicodins.

Tommy Marth -- a saxophone player for The Killers -- was found dead at his Las Vegas home Monday ... and according to reports, the death has been ruled a suicide.

The Killers released a statement on Tuesday ... saying, "Last night we lost our friend Thomas Marth. Our prayers are with his family. There’s a light missing in Las Vegas tonight. Travel well, Tommy.”

Marth played sax on two Killers albums -- Sam's Town and Day & Age. He also toured with the band in 2008 and 2009. He was 33.

Andrew Breitbart died of heart failure stemming from coronary disease, this according to the L.A. County coroner's office.

A spokesman for the coroner's office says there were minute traces of alcohol in his system, but has ruled no foul play and closed the case.

The conservative blogger -- who founded the popular news site Breitbart.com -- died March 2 at UCLA medical center after collapsing near his Brentwood home.

"Real Housewives of New York City" star Alex McCord and her family are dealing with a real tragedy -- their beloved cat Madge passed away this week after she was hit by a car.

Neighbors discovered the cat lying in the street on Wednesday after she managed to get out of the house. McCord said Madge's body was still in perfect condition, so the family (including their other cat Erin) was able to say their goodbyes.

McCord says the death of Madge has been difficult to explain to her two boys, adding, "We talked about how … she was different because she wasn't alive anymore. They each wrote her a little note which we put in a box we buried her in and put a marker above her grave."

The Band singer/drummer Levon Helm -- famous for hits like "The Weight" ("Take a load off Annie" ...) -- has died after a long battle with throat cancer.

Helm -- diagnosed with throat cancer in the late 90s -- passed away this afternoon in NYC, surrounded by his friends and bandmates.

Helm formed what would eventually become The Band with Robbie Robertson, Richard Manuel, Rick Danko and Garth Hudson in 1964.

The group went by various names -- but didn't become the "The Band" until after they toured with Bob Dylan in 1965 and 1966 ... a reference to their back-up band history with various frontmen.

Helm has won 3 Grammys for his solo work in the last 4 years. In 2008, The Band received the Grammys' Lifetime Achievement Award.

Helm is survived by his wife and daughter. He was 71.

Dick Clark -- famed TV producer and "New Year's Rockin' Eve" host -- died from a massive heart attack this morning ... TMZ has learned.

Clark's rep tells TMZ, the TV icon had been in St. John's hospital in L.A. after undergoing an outpatient procedure last night. Clark suffered the "massive" heart attack following the procedure. Attempts to resuscitate him were unsuccessful.

Clark was 82.

Clark's health had been on the decline since he suffered a significant stroke in 2004 -- forcing him to retire from his hosting gig at "New Year's Rockin' Eve," which he created in 1972. Ryan Seacrest took over in 2006. Dick has appeared on the show sporadically ever since. His final appearance was in 2011.

Months before suffering a stroke, Clark told Larry King he also suffered from Type 2 diabetes.

Clark got his first big break in 1956, hosting what was called "Bob Horn's Bandstand" ... what would later be renamed "American Bandstand." Clark continued to host and produce "American Bandstand" until 1989.

Dick hosted Miss USA from 1989-1993 -- and Miss Universe 1990-1993.

In addition, Clark also hosted a bunch of game shows -- like "Pyramid," "Scattergories," "The Challengers," and many more.

Clark had been inducted into practically every hall of fame on the planet -- including the Hollywood Walk of Fame, the Rock and Roll Hall of Fame, and the Academy of Television Arts and Sciences Hall of Fame.

Clark had also received a total of 5 Emmy Awards for his work, as well as a Peabody Award. One Emmy was a lifetime achievement award.

Clark was married 3 times -- and has 3 children from his first two marriages. He is survived by his current wife Kari Wigton.

"For now, Dick Clark ... so long."

5:20 PM PT: Dick Clark's rep tells TMZ, there will be NO public funeral. In lieu of flowers, Dick's family asks that donations be made to the National Parkinson’s Foundation based in Miami.

Ryan Seacrest just tweeted, writing, "I am deeply saddened by the loss of my dear friend Dick Clark. He has truly been one of the greatest influences in my life."

Donny Osmond tells us, "The industry lost a legend today, but I feel like I've lost a very close friend. Dick was a mentor to me."

The President of Miss Universe Paula Shugart -- who started working for Dick Clark Productions in 1985 -- tells TMZ, Dick "gave me my first break in TV. His death is hitting all of us hard."

The Internet's EXPLODING with reactions from celebrities -- click here for live updates.