Son of Arnold Schwarzenegger and Maria Shriver in Hospital After Surfing Accident

Arnold Schwarzenegger and Maria Shriver face another family crisis as their youngest son Christopher is in ICU following a serious surfing accident. INSIDE EDITION has the latest details.

Arnold Schwarzenegger and Maria Shriver's youngest son is in the hospital after a terrifying surfing accident.

It happened in Malibu, California. 13-year-old Christopher Schwarzenegger wiped out while boogie boarding in rough waters and suffered multiple broken bones and a collapsed lung. Shriver watched it all happen and rushed him to the hospital. Christopher's condition was so serious that he was put in intensive care.

Shriver has barely left his side, even sleeping at the hospital. Schwarzenegger has been a regular visitor.

Christopher's oldest brother, Patrick, tweeted: "Thank you everyone for your messages about my brother. This kid is strongest kid I ever seen. Keep praying."

Big sister Katherine also took to Twitter, saying: "Thank you guys for ur concern and prayers for my baby brother! He's a tough little guy and getting better!"

Of the four Schwarzenegger kids, Christopher seemed to take his parents' divorce the hardest. His dad's love child with the family maid is the same age as Christopher. They were born just five days apart. As the scandal made headlines across the world, Schwarzenegger and Shriver were seen paying special attention to Chris. Editor-in-Chief Bonnie Fuller told INSIDE EDITION, "What happened between Arnold and Maria has to have been incredibly tough on poor Christopher. First of all, at 13 he's the youngest in the family, the baby. And he finds out now that he's got a half-brother."

The accident happened on Sunday, but amazingly the Schwarzeneggers were able to keep the news private until it was leaked today.

Earlier this week, Schwarzenegger filed new court papers arguing that he shouldn't have to pay spousal support to Shriver, or her attorney fees.

"The good thing is, Arnold and Maria have put aside their differences to take care of their son," said Fuller.

Surfers say a wipeout in a crushing wave can feel like every bone in your body is breaking. The beach at Malibu is a popular surfer hangout, but rocky outcrops can make it a dangerous spot.

Now the embattled Schwarzenegger family has come together to help young Christopher get well. The latest from the hospital is that his condition has been upgraded and he's on the road to recovery.