YUCAIPA, Calif. (AP) -- The bus full of tired tourists from Mexico was slowly winding its way down the mountain from the ski resort town of Big Bear when it suddenly picked up speed. The driver shouted to call 911 -- the brakes had failed.
As passengers frantically tried to get a cellphone signal, a group of teenage girls shrieked and prayed aloud as others cried and shielded their heads as they careened downhill.
The bus rear-ended a Saturn sedan, swerved, flipped and slid on its side. A Ford pickup in the oncoming lane plowed into it, righting the bus and tossing passengers out shattered windows before it came to a halt.
"Everything happened so fast. When the bus spun everything flew, even the people," said Gerardo Barrientos, who was next to his girlfriend one minute and then scrambling out of the wreckage the next moment to find her and a friend in the highway, injured but alive among the carnage.
Seven people were killed and dozens injured Sunday in the accident 80 miles east of Los Angeles. On Monday, families from Tijuana anxiously sought loved ones in hospitals and investigators searched the scene for evidence and scrutinized the company's safety history.
Government records showed the bus, operated by Scapadas Magicas of National City, Calif., recorded 22 safety violations in inspections over a year -- including brake, windshield and tire problems.
The crash littered State Route 38 with body parts, winter clothing and debris. The bus stood across both lanes with its windows blown out, front end crushed and part of the roof peeled back like a tin can.
"I saw many people dead. There are very, very horrendous images in my head, things I don't want to think about," Barrientos said as he and girlfriend Lluvia Ramirez, who both work at a government hospital in Tijuana, waited outside the Loma Linda University Medical Center emergency room for word on a friend who broke her neck.
After the crash, Barrientos, who was uninjured, moved his friends to safety and then tried to help the bus driver, whose hand was pinned between rocks.
Ramirez, who had a bloody ear, dark bruises and a scratch on her neck, suffered a hairline vertebra fracture.
"I was overwhelmed," she said. "I'm a surgical resident and I usually know how to react, but I was so in shock I didn't know what to do. I just stayed with my friend."
The bus was going slowly down the hill and was being passed by other vehicles, including the Saturn, when it suddenly sped up for an unknown reason, according to a person involved in the investigation who requested anonymity because the probe was ongoing.
The bus traveled about a mile from the point it struck the Saturn until it came to a stop, said California Highway Patrol Officer Leon Lopez.
Investigators will determine if mechanical failure or driver error was to blame. The road, which sometimes closes in winter during snow storms, was dry at the time.
The bus driver, Norberto B. Perez, approximately 52, of San Ysidro, was in serious condition, authorities said.
The driver told investigators the vehicle had brake problems.
The National Transportation Safety Board sent a team to the scene to help in the probe.
Federal transportation records show the bus company was licensed to carry passengers for interstate travel and that it had no crashes in the past two years.
Stephen Keppler of the Commercial Vehicle Safety Alliance, a group with industry and government members, said buses and trucks average about two violations for each inspection.
Overall, buses operated by the firm flunked 36 percent of random inspections, the records indicate. That's higher than the national average for similar companies -- a 21 percent failure rate.
The California company had an overall "satisfactory" rating from the Federal Motor Carrier Safety Administration -- but records show three-quarters of similar companies had better safety records.
No one answered the door at the Scapadas Magicas office in a sprawling complex that houses more than 1,300 storage lockers and about 30 small offices.
The bus left Tijuana early Sunday for the three-hour ride to ferry people up to Big Bear for a day in the snow.
Crews worked through the night to recover the dead, removing the last body Monday afternoon.
At least 17 people were still hospitalized, including at least five in critical condition. One is a girl.
The pickup driver was in extremely serious condition, said Peter Brierty, assistant county fire chief. Three people were in the Saturn.
Rocky Shaw, San Bernardino County coroner's investigation, said one of the dead victims was a 13-year-old boy. The boy's family from Tijuana was meeting with Mexican Consulate officials after spending the night going from hospital to hospital looking for him.
Jordi Garcia, marketing director of Interbus, said his company rented the bus from Scapadas Magicas, which supplied the driver.
Interbus offers Mexicans near-daily bus tours to the western U.S. from Tijuana. Its office in a Tijuana strip mall displays photographs of some of its destinations, including Hollywood, the Las Vegas Strip and the San Diego Zoo.
There were 38 people aboard the bus that crashed, including the driver and a tour guide, Garcia said. The bus left Tijuana at 5 a.m. Sunday, with the itinerary calling for a return late that night.
"Everything points to faulty brakes," Garcia said.
He said he spoke briefly with his tour guide, who suffered bruises. She told him she heard a loud pop before the crash.
Garcia said he believed all passengers were Mexican citizens, but one mother said her injured daughter was a U.S. citizen.
Big Bear Lake sits at an elevation of 6,750 feet, and the area has ski resorts and other snow play areas.
Associated Press writers contributing to this report included Gillian Flaccus in Loma Linda, Raquel Maria Dillon in San Bernardino County, Michael R. Blood, Andrew Dalton and Bob Jablon in Los Angeles, Amanda Kwan and Bob Seavey in Phoenix