A 13-year-old boy has lost his life and his 8-year-old sibling is in critical condition at a California hospital.

The Associated Press reported that the one boy is still fighting for his life after his family left a resort and their vehicle plunged into the waters of the Los Angeles Harbor.

Authorities said that the car became fully submerged and both parents swam to the surface, however, neither boy was breathing at the time that they were brought up.

"(The man) came up out of the water and swam pretty fast up to one of these ladders" at the dock," witness Frank Palazzolo told the Los Angeles News Group paper. "The (mother), she came up hovering over the car and I thought she was drowning. She was going crazy. She was screaming, 'My kids, my kids,' screaming real loud."

The older sibling later died at the hospital, police said. And as of now, the case is being investigated as an accident.

Firefighters at the scene said the parents were both in fair condition when they emerged from the murky water.