One boy died and another was clinging to life Thursday after their parents’ car plunged into the Main Channel at the Ports O’ Call Village parking lot and sank 30 feet into the murky water.

Firefighters made a desperate effort to save the trapped children after finding their parents swimming in the water when they responded to the accident at 6:10 p.m. at Berth 73

“(The man) came up out of the water and swam pretty fast up to one of these ladders” at the dock,” said witness Frank Palazzolo, 15, of San Pedro. “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.”

One firefighter, Miguel Meza, stripped off his clothes and jumped into the water. Fire Department divers pulled the parents to safety and plunged underwater to go after the children, who witnesses said were submerged for 10 to 15 minutes before they were brought to the surface.

“The diver came up with the kid and he was just floating. He was lifeless,” Palazzolo said.

Los Angeles City Fire Department spokesman Brian Humphrey said both boys were pulseless and not breathing when brought to land.

The ages of the children were not immediately known.

Firefighters repeatedly questioned the adults to determine whether any other occupants of the car were still underwater. Divers searched every area of the blue Toyota to make sure no one else was still trapped.

“They forced open the trunk of the vehicle,” Humphrey said. “They could barely see their hands in front of their faces.”

The adults, who were speaking Spanish to rescuers, were reported to be in fair condition, Humphrey said. One boy died at a hospital, while the other child was reported to be in grave condition.

Aerial shots from a television helicopter showed paramedics performing cardiopulmonary resuscitation on one of the children when they arrived at County Harbor-UCLA Medical Center.

Los Angeles Police Department South Traffic Bureau detectives responded to investigate the crash. Preliminarily, Humphrey said, it appeared to be just a terrible accident, but Los Angeles police Capt. Brian Whitten said later, “We don’t know if the vehicle was driven into the water intentionally.”

Witness Sal Terzoli of San Pedro said he was working on his fishing boat Ocean Pride when he heard tires screeching. He looked across and saw the Toyota traveling 20-30 mph crash into the water.

Terzoli said it took just a few seconds for the car to sink.

Palazzolo, who was with Terzoli, estimated the car was moving at 15 mph at a 45-degree angle to the channel, as if the driver was going to park.

“It looks like they sped up … and went down real quick, about 30 feet out,” he said. “They were going pretty fast.”

He suggested the driver mistook the gas pedal for the brake.

“That’s what it looked like, because they had some speed,” the teen said.

One detective told Palazzolo the boys were 11 and 14 years old.

The mother stood on the dock as firefighters rolled one of the boys on a stretcher toward an ambulance.

“She was blank,” Palazzolo said. “She wasn’t saying anything. She was just leaning up against the pole.”

The witnesses said the car went over the dock at an area without log pilings sticking up to block its path. The area is designated for fishermen to fix their nets.

“I’ve been down here for 25 years and this is the first time I’ve seen something like this,” Terzoli said. “It was like a movie.”