Nurse!

Whitney Houston's daughter Bobbi Kristina has "significantly diminished" brain function and doctors have told her family it does not look good ... this according to sources connected with the family.

As we previously reported, the 21-year-old was found face down in her bathtub Saturday and not breathing. She was revived, taken to the hospital where she was placed in a medically-induced coma.

She is currently on a ventilator but we're told tests have determined her brain function is alarmingly low.

Bobbi Kristina's dad, Bobby Brown, is at her bedside.

Doctors have told the family they should continue hoping and praying, but the signs are not good.

Ex-NFL star Titus Young is suffering from a traumatic brain injury caused by repeated blows to the head ... which contributed to his alleged violent behavior ... so say the specialists treating Young at a mental health facility in San Diego.

As we previously reported, the 25-year-old former Detroit Lions receiver was arrested last year after allegedly attacking people in 5 separate incidents ... and was locked up in a L.A. County jail.

Now, we've learned Young recently bonded out and has been receiving treatment at the Crosby Center in S.D. -- where specialists believe Young's issues come from the hits he took playing football.

TMZ Sports spoke with Pete Daniels, intake coordinator at the Center, who tells us Young was admitted to the facility last weekend and has been working with a team of specialists and doctors non-stop.

Despite the short stay, Daniels says the doctors say Young's symptoms include hypervigilance, mood swings, emotional instability and more.

"All of the these are results of Young taking hits to the head for long periods of time," Daniels says ... "without a doubt."

Daniels says Young has been responding positively to the treatment -- he's feeling better and more in control of his life.

Young -- who's still facing criminal charges for the alleged assaults -- is expected to remain at the center for least 6 more weeks. Daniels says he hopes the judge will allow him to continue treatment instead of putting him back behind bars.

6:05 PM PT -- Sources close to the family tell TMZ Bobby Brown has arrived at the hospital with Tyler Perry and the two are at Bobbi Kristina's bedside. We're told Tyler was flying from LA to Atlanta for business and offered to take Bobby with him when the news broke.

1:53 PM PT -- Sources close to the family tell TMZ Bobbi Kristina has been placed in a medically induced coma for swelling of the brain.

Whitney Houston and Bobby Brown's daughter was found unconscious in a bathtub in her home -- and taken to a hospital where she is now breathing ... TMZ has learned.

Bobbi Kristina Brown's husband Nick Gordon and a friend found her in the tub ... according to police in Roswell, GA. We're told her husband and friend immediately started CPR on her ... until police and paramedics arrived.

We're told police took over life-saving measures on the scene -- and then she was taken by ambulance to a hospital.

Doctors have now stabilized her breathing, and we're told she is in ICU.

Still unclear why Bobbi fell unconscious. We're told a friend made the call to 911 from Bobbi's house.

The circumstances are especially eerie -- Whitney was found dead in a bathtub at the Beverly Hilton on February 11 ... three years ago.

Story developing ...

Bobbi Kristina was face down in the bathtub when she was found this morning, and police searched her home for drugs ... TMZ has learned.

Law enforcement sources tell us when Nick Gordon and a friend found Bobbi Kristina she was on her stomach, and there was water in the tub. It's unclear how full the tub was, but we're told it was enough water for a bath.

The significance, of course, is that Whitney Houston died with drugs in her system ... while taking a bath 3 years ago at the Beverly Hilton.

We've also learned police executed a search warrant on the home this afternoon, and we're told no drugs were found.

Tracy Morgan is taking it step by step as he continues his recovery from that horrible truck accident.

Tracy is still walking with assistance, showing clear signs the June crash has taken its toll.

Chicago Bears fans can take a deep breath, 'cause Brandon Marshall's punctured lung is doing MUCH better ... so say his doctors who allowed the WR to begin flying again ... TMZ Sports has learned.

We broke the story ... Marshall had to miss a court-ordered deposition last month stemming from a case in which he's accused of attacking a woman outside of a NYC nightclub in 2012.

Marshall claimed doctors told him it was unsafe to fly since he had just suffered a punctured lung from a hit he took during a Thursday Night Football game.

But everything's been healing well ... and earlier this month, Marshall told the court he's been cleared for takeoff ... and was willing and able to attend a makeup depo on January 30th.

Sources tell us Marshall made his appointment and sat for a deposition without a hitch ... or a breathing issue.

5:30 PM PT -- A rep for Val tells TMZ that the actor is currently undergoing tests for a possible tumor. Doctors are encouraged by his progress and hopeful he will make a full recovery.

8:50 AM PT -- Val has released the following statement on his Facebook page -- "Thank you for all your sweet support. But I have not had a tumor, or a tumor operations, or any operation. I had a complication where the best way to receive care was to stay under the watchful eye of the ucla ICU. Friends have assisted who know my spiritual convictions and have been most sensitive and kind for the extra effort in making sure there's minimum gossip and silly talk. I am praying for a speedy return to the boards as they say. God bless you all and please don't worry. Love and deep affection , Val."

Val Kilmer was rushed to a hospital this week after he began bleeding from the throat ... and we're told it's a throat tumor.

Law enforcement sources tell us paramedics rushed to his Malibu home Monday night after someone called 911 and reported the bleeding.

The "Top Gun" star was taken to UCLA Medical Center, Santa Monica. Doctors performed surgery and he's currently recovering.

We're told family members have been upset because they feel Val has ignored the problem and allowed it to get worse.

In October Val was in small claims court over a dispute with his former landlord and he told the judge he was unable to speak because his tongue was swollen.

Kilmer was last seen in public at a Clippers game with his son Jack. Val had his neck covered during the game.

Big day for Leah Still -- because her father told us the 4-year-old starts a new round of chemotherapy this morning that will hopefully crush her disease so badly, she can finally begin stem cell therapy.

Cincinnati Bengals defensive lineman Devon Still is out in AZ -- and told us that while the cancer is still in Leah's body, she's fighting like hell to beat it.

"We're just hoping for the best and just trusting in the doctors to their best for her," Still told us.

Still also told us why he and Leah decided to write a children's book about Leah's battle with pediatric cancer -- and it's truly inspiring stuff.

"Harry Potter" star Robbie Coltrane got off a plane Thursday and was immediately hospitalized after suffering severe flu-like symptoms during the flight ... TMZ has learned.

A rep for Coltrane -- who played Rubeus Hagrid -- tells us the actor fell ill during a British Airways flight from London to Orlando.

We're told paramedics met Coltrane at the gate, and took him to the hospital ... where he'll remain overnight for treatment.

Coltrane went to Orlando for a Harry Potter convention ... and we're told Michael Gambon -- who played Dumbledore -- was on the same flight.

Someone on Twitter claims Coltrane was drinking heavily in a London airport lounge before the flight. If it's true, we don't know yet if that contributed to his illness.

Lindsay Lohan wasn't lying when she said she picked up the chikungunya virus while vacationing in Bora Bora ... because her doctor says that's exactly what was ailing her.

Lindsay's lawyer, Shawn Holley, told us as she left the courthouse, the doctor's notes she submitted to the judge this AM validated what Lindsay claimed.

Boxing champ Jermain Taylor has been ordered to undergo a mental evaluation ... after a string of arrests and strange behavior that clearly raised some red flags with an Arkansas judge.

Taylor's own attorneys had asked the judge to move the 36-year-old to a state hospital for a full mental evaluation ... after he turned himself in for allegedly firing a gun during an altercation with a family at a Martin Luther King Day parade.

As we previously reported, Taylor kinda sorta acknowledged he fired the gun in a bizarre YouTube video ... in which he blamed his outburst on the fact that several kids at the parade did not have candy.

Taylor has been charged with aggravated assault and endangering the welfare of a minor for the incident. Prosecutors believe Taylor is a danger to himself and others.

The results of Taylor's mental evaluation are scheduled to be presented to the court in April.

"Everybody is saying this isn't the Jermain Taylor they know," Taylor's attorney told ArkansasOnline.com ... "We're trying to figure out who in the heck it is."

Melissa Rivers has just filed a huge lawsuit against the clinic where Joan Rivers' heart stopped beating ... and Melissa's lawyer says the doctors acted like a bunch of groupies and not medical professionals.

The lawsuit -- obtained by TMZ -- claims gross medical malpractice, alleging during the 20 minutes doctors tried to bring Joan back to life, they didn't think to perform a tracheotomy, which facilitates breathing.

Melissa says, "The level of medical mismanagement, incompetency, disrespect and outrageous behavior is shocking and frankly, almost incomprehensible," adding, "Not only did my mother deserve better, every patient deserves better."

In addition to suing the clinic, Melissa has sued Joan's personal doctor, Gwen Korovin. According to the lawsuit, she should not have been permitted in the room where the procedure was being performed, yet she jumped in and announced, "I'll go first."

The suit claims another doctor took cellphone pics of Rivers before the emergency, while she was under sedation, with Korovin in the photos, saying Joan "will like to see these in the recovery area."

According to the lawsuit, Korovin left the room in the middle of the emergency and the allegation is that she left because she knew she wasn't supposed to be there in the first place and "wanted to avoid getting caught." The suit says Korovin simply abandoned Joan.

And get this. According to the suit, in the middle of the emergency, another doctor took issue with a colleague who wanted to scope the affected area, saying, "Renuka, you're such a curious cat. You always want to know what's going on." The suit says the doctor refused to authorize the scope.

Melissa's lawyer spoke to The NY Daily News, which broke the story, and quotes lawyer Jeffrey Bloom who says, "Had doctors acted as physicians for Joan Rivers instead of groupies, Joan Rivers would have been doing 'Fashion Police' last week."

Yorkville Endoscopy has been under intense scrutiny and they are set to lose their accreditation at the end of the month.

Richard Simmons had visitors Friday night ... cops who were doing a welfare check because he's been MIA for more than year ... and guess what? He's fine.

Law enforcement sources tell TMZ ... 2 LAPD officers showed up to Simmons' Hollywood Hills home at 7 PM. Richard answered the door and showed them in. The cops' feedback -- he couldn't have been nicer and more gracious. They say he was articulate, lucid, relaxed and appreciative of their concern.

Law enforcement sources tell TMZ ... the visit was triggered by a long-time friend of Simmons who sent an email to the L.A. County D.A.'s Elder Abuse Unit last month and said he believed the 66-year-old fitness guru was being abused.

TMZ broke the story, Simmons went radio silent a year ago. He hasn't spoken to his friends, gone to his fitness studio or been seen in public. His friends say there is no way Richard would shut himself off this way. His manager says Simmons is simply depressed over a knee injury.

But we've learned the 2 cops who spent an hour with Richard say he seemed genuinely happy. Simmons, who now has a beard, told them he was "exhausted" after spending 30 years in the public eye. He said, "I just want to spend time with myself," although he says he's in regular touch with the people in his life who matter to him. He was alone in the house Friday when cops were there.

Simmons was walking with a slight limp, which is consistent with the knee injury. As for why he hasn't been to his fitness studio for the better part of last year, he said, "I've got people who run things. I don't need to be there." Until he disappeared he was a fixture at the studio.

Pro skier Henrik Harlaut was knocked out cold Saturday during an X Games Aspen event ... and the footage is frightening.

It all went down during the Men's Slopestyle finals ... when Harlaut landed a trick the wrong way and took a gnarly tumble -- leaving the 23 year-old motionless as medics rushed in to help.

The Swedish skier eventually sat up before being stretchered off the mountain ... and waved to everyone letting them know he's OK while plastering a giant smile across his face.

Casper Smart's dog escaped from Jennifer Lopez's house and bit one of her neighbors ... leaving the woman with a broken hand.

Law enforcement sources tell TMZ ... Smart's boxer, named Bear was at JLo's home outside Los Angeles back in December ... when he got loose and clamped down on the neighbor's hand and arm.

Since the attack, Bear has been quarantined at Casper's nearby Woodland Hills home. Authorities are still trying to determine if the dog poses a danger to others.

We're told both of Casper's boxers still spend a lot of time at JLo's house ... since her kids love the dogs. It's unclear if JLo or Casper were at the house when the attack happened, but Animal Control gave Casper a citation for an unleashed dog ... since he's the owner.

Whoopi Goldberg's got back ... problems and it's creating a rift between her, the other "View" co-hosts and producers of the show -- who think Whoopi's new chair is a major eyesore.

When Whoopi returned from her two-week injury sabbatical Tuesday, she brought a new ergonomic chair for support. All the women used the same chair ... so Whoopi's wouldn't look different.

According to our sources, producers felt the chairs looked clunky on camera ... so they yanked them for Wednesday's episode -- but Whoopi stood (or sat) her ground in the new chair.

And yes ... it stood out.

We're told Whoopi has no plans to change back, so producers are struggling to find a way to make it more pleasing to the eye.