Nurse!

Mark Ballas was in a bad car accident Monday afternoon and ended up in an L.A. hospital ... TMZ has learned.

We're told Mark was driving on an L.A. street, in the process of turning right, when another car was speeding in his lane, couldn't stop in time and slammed into his back right side.

Mark complained of whiplash and back pain. His girlfriend took him to Cedars-Sinai Medial Center where doctors examined him and prescribed some pain meds. Doctors told him the pain would get worse tomorrow, which isn't great news because Mark is scheduled to perform this week where he'll have a guitar strapped to his body as he sings and dances.

Two "It's Always Sunny in Philadelphia" stars are being sued after their dog allegedly attacked a 19-month-old and bit her on the face ... TMZ has learned.

According to a lawsuit filed today in L.A. Superior Court, Kaitlin Olson and Rob McElhenney (Dee and Mac) had a Father's Day party back in 2012 ... and the couple's German shepherd was off the leash when it bit the toddler "without provocation."

The child's mom, Julie DeLagarde, says she let it be known she didn't want her daughter around the dog ... but Kaitlin and Rob (who are married) did not leash the dog.

DeLagarde claims the area next to her daughter's mouth, including part of her cheek, was "hanging off with all the insides of her face exposed and blood streaming everywhere."

DeLagarde has blogged about the ordeal and posted pics of the child's scars.

In the suit, she says her daughter will be scarred for the rest of her life unless she has additional plastic surgeries down the road.

"Survivor" villain Jonny Fairplay got tossed in the air by an angry buff guy Thursday and broke his finger in the process -- only this time, Danny Bonaduce wasn't involved.

Jonny says he broke his ring finger this week playing in an adult kickball league ... after a large man bum rushed him at second base, knocking Fairplay high into the air.

The "Survivor" star got checked out by a doctor after the game -- they said he also tore a tendon in his middle finger -- but for now he won't need surgery, just a splint and some tape.

Zsa Zsa Gabor's husband Prince Frederic von Anhalt says a plastic surgeon botched a routine operation on his face ... and now he's left looking like a mutated German version of Professor X.

Prince tells us he went in for cosmetic surgery Monday but the procedure went horribly awry ... and now the 70-year-old wants to take legal action.

A-hole's lawyer wouldn't get specific on the procedure -- but we're told he'll file suit if the damage is not reversible

Street artist Retna claims his fight with Brittny Gastineau was mutual ... but TMZ has learned he's had other alleged incidents of violence ... with 3 restraining orders over 2 separate attacks.

As TMZ first reported, Gastineau claims her black eye is the remaining visible sign of a viscious attack in a West Hollywood hotel room 2 weeks ago. Retna's lawyer claims Gastineau started the whole thing and Retna was defenseless -- recovering from knee surgery.

But Retna was accused of 2 other violent confrontations in the past 2 years. In late 2012, he was charged with 3 counts of battery after allegedly going ballistic on the employees at an art gallery in L.A.

According to one of the victims, Retna punched two of the employees in the head (one of them he hit so hard it broke the pencil in his ear) ... then left the store ... only to come back later and hit a third.

The case never went to trial -- but Retna was ordered to stay away from the gallery.

Then in July of 2013, Retna allegedly harassed 2 other art gallery employees ... According to the restraining order, Retna ripped and destroyed paintings with knives and beer bottles.

One of the employees claimed Retna tried to strangle him and made crazy threats, including this: "Next time I see you I'm going to take your TONGUE out of your mouth n wrap it around your nexk and staple ur ass to the backboard n charge the kids in the neighborhood 25 cents. To throw rocks at ur some n stone u to death. Booyah."

The force is not strong with this one -- and not only because he's not a Jedi ... but Harrison Ford was injured today on the set of "Star Wars: Episode VII."

A Disney rep confirms Ford injured his ankle and was taken to a local hospital.

According to the Hollywood Reporter, he was hit by a door on the Millennium Falcon ... which, as TMZ first showed you, is making its triumphant return to the franchise.

The Disney rep added that 71-year-old Harrison's injury will not affect the shooting schedule for the movie.

Casey Kasem is living out the final days of his life by listening to the best days ... his family has been playing old recordings of his "American Top 40" show while he lay dying in hospice.

Casey is currently in a Washington hospice with his family by his side ... including his daughters, son, and brother. Family sources tell us ... the family is playing old broadcasts of Kasem's legendary radio show ... the crowning achievement of his career.

Now that the family has stopped giving him medication, food, and water ... they're just trying to make him as comfortable as possible ... and they believe the broadcasts will give him great enjoyment.

Legendary DJ Casey Kasem will live out his final days this week surrounded by his children ... who have made the decision to withhold medication, food and fluids.

The judge in Casey's conservatorship case just reversed a ruling which required doctors to keep him alive with nourishment and meds.

The 82-year-old is currently in a Washington hospice facility.

Casey's kids tell TMZ ... their dad's health directive document states, "If the extension of my life would result in mere biological existence, devoid of cognitive function, with no reasonable hope for normal functioning, then I do not desire any form of life-sustaining procedures, including nutrition and hydration."

Casey's wife Jean was in court and furious over the judge's decision, storming out and screaming that the kids will have Casey's blood on their hands.

Kevin Roper -- the truck driver facing charges over the fatal crash that involved Tracy Morgan -- pled not guilty in a New Brunswick court this afternoon.

Roper is facing charges of death by auto and assault by auto. His bail was set at $50,000.

Roper was driving a truck for Walmart on Saturday when he struck Morgan's limo. One person died as a result and Morgan is still in the hospital in critical condition.

The man who allegedly viciously attacked Brittny Gastineau was himself badly injured during their altercation ... and his lawyer tells TMZ it was a case of mutual combat.

Marquis Lewis -- a famous street artist who goes by the name Retna -- was dating Brittny. He had checked into the London Hotel in West Hollywood a week ago Monday to recuperate from major knee surgery -- surgery that had just been performed.

Retna's lawyer, Michael Goldstein, tells TMZ ... Brittny came to visit a week ago Tuesday night and they got into a major argument.

Goldstein says his client was almost defenseless from the physical attack because he was unable to walk without crutches. We're told there was lots of swinging, and in the end Retna was also seriously injured -- his face and eye were swollen, his painting hand was injured and his ear was cut up.

Goldstein says, "Retna was not the aggressor." That said, Goldstein tells TMZ his client harbors no ill will, calling Brittny "sweet." He says, "They're cool with each other."

Goldstein says Retna and Brittny are in the process of settling their differences and he's surprised Brittny made a spectacle last night at paparazzi-riddled restaurants.

Brittny Gastineau was savagely attacked in a West Hollywood hotel room and cops are now involved ... sources familiar with the situation tell TMZ.

Our sources say ... Brittny was at the London Hotel with a male companion -- a man who himself has some fame. We're told Brittny claims the man beat her up badly in the room ... so badly she had to go to the hospital.

Doctors at the hospital felt there was a domestic violence situation and called the police. We're told the police then came to the hospital and interviewed Brittny.

The injuries had to be gruesome, because Brittny was out last night (see pic) -- the attack occurred more than a week ago, and this is what she still looks like.

Brittny Gastineau wanted everyone to know ... she got a wicked black eye from someone or something.

Kim Kardashian's BFF showed up at Craig's restaurant in West Hollywood Tuesday night -- the place to go if you want to be photographed by paparazzi. She went there with her mom, who told photogs, "You know, Angels, when they hit earth, it hurts a lot." But they weren't specific.

Now ... if you think they didn't go to Craig's to be photographed, think again, because earlier in the evening they went to Mr. Chow in Bev Hills, the other place in town where you are certain to get papped.

So we're left with this mystery -- who eats 2 dinners?

Tracy Morgan's estranged mother was turned away at the hospital when she first went to visit her critically injured son ... this according to the mother herself.

Alicia Warden -- who has had a well-publicized, strained relationship with Morgan -- tells TMZ no one called her about her son ... she heard about it on TV.

She says she went to visit Tracy in the hospital on Saturday, but was turned away by hospital security and Tracy's fiancee, Megan Wollover. Warden believes Tracy's fiancee has a thing against her.

Warden says she returned the next day and she was let in ... but Tracy was unconscious and she was only allowed to stay for 5 minutes -- never alone with him. She says his friends and a pastor were in the room.

Warden says, "All I wanted was for our family to be alone with him. I wanted to pray over him and couldn’t do that because so many people were in the room."

The trucker who caused the fatal car crash that left Tracy Morgan in critical condition says he was not high on drugs or drunk when he slammed into the SUV ... and believes he's being skewered because a celeb was hurt in the accident.

A twitter account which appears to be Walmart trucker Kevin Roper was very active early Tuesday morning ... with a remorseful Roper saying, "I wish it was me and I can't express how horrible I feel."

Roper also denies reports he hadn't slept for 24 hours, claiming the bad press is all about finding a scapegoat, as he says, "because a famous person was involved." He wrote, "I was never charged at the scene of the accident because once again i was not guilty of any crime. Not until all the TV cameras came."

Roper seems to say he was not negligent and therefore not responsible for the crash, suggesting he was not at fault.

Tracy Morgan's deadly 6-car pileup should be an alarm for New Jersey officials to make some big changes before more lives are lost ... this according to the family of a truck driver who died on the same dangerous stretch of highway.

The Walmart truck that plowed into Tracy's vehicle was hurtling down the NJ Turnpike -- and back in April, just a few miles away ... John Visconti III was killed in an eerily similar crash.

TMZ spoke to his mother, Mary Visconti who was outraged by the carnage of Morgan's accident ... "How many people have to die on the Turnpike before something is done? It is ridiculous."

Mary says her son was driving an 18-wheeler when he swerved to avoid a much slower vehicle on the highway. He was killed when his truck overturned and caught fire.

While the truck driver in Morgan's wreck allegedly dozed off -- Mary thinks the bigger issue is out of control speeding on the Turnpike ... and she thinks it's time to lower the limit from 65 to 55.

It's gonna be way harder to find good help for rapper Mickey Avalon ... whose housekeeper claims she was practically electrocuted by his dirty oven.

Lula Malone claims she was cleaning the oven in Avalon's L.A. home last month when she was jolted by an electric shock ... according to the lawsuit she just filed.

Malone says she suffered serious injury and in the legal docs -- obtained by TMZ -- she blames Avalon because his home and oven were "maintained in an unsafe manner." Malone doesn't explain any specific hazards of the oven.

Malone says she's screwed because Avalon doesn't have workers' comp insurance to cover her injuries. She's suing "Mr. Right" for her medical expenses and lost wages.

We reached out to Mickey's reps -- so far no word back.