Authorities in San Diego were trying to determine Sunday why the driver of a pickup lost control of his truck on a highway bridge, swerved over a retaining wall and plunged 60 feet into a park, killing four people at a biker festival.
Police said Richard Anthony Sepolio, a Navy member stationed at Naval Base Coronado, was arrested on suspicion of driving under the influence causing death.
"It's horrible, it's horrific," California Highway Patrol Officer Jake Sanchez said late Saturday. "There were people down below. ... Innocent people that were just down there having a good time and now they are gone."
Sanchez said the four people who died were killed almost instantly. Sepolio, 25, and one person on the ground in Chicano Park survived with "major" injuries, Sanchez said. Seven other people also were injured.
"Praying for victims & families affected by the tragedy in Chicano Park. Devastated this occurred in one of our community's most beloved places," Mayor Kevin Faulconer tweeted.
Sanchez said two of the victims were from Chandler, Ariz., and two from suburban Los Angeles. The festival marked La Raza Run, an annual motorcycle ride from Los Angeles to San Diego that can draw more than 1,000 bikers. The festival features food, music, art and tables of vendors selling shirts and other goods.
Victims described the scene as the truck crashed onto a vendor's table where people had crowded around to buy and sell T-shirts.
"All I heard was a boom, and all of a sudden we just see this truck flying down," witness John Vazquez told the local ABC-TV affiliate. "We see this truck just falling off of the bridge and it lands on the booth nose first."
Vazquez said the driver had his cellphone in his hand when the truck landed.
Iris Jimenez, 29, told The San Diego Union-Tribune two bikers she described as "very nice people" and two vendors were killed. She said her companion, Pedro Sanchez, rushed to help a group of men lift the pickup off the victims.
“I saw the truck coming at me, and if I hadn’t run, I’d be dead,” Jimenez told the newspaper.
Dolores D'Angelo told nbcsandiego.com has been singing with a band at the festival when she witnessed tragedy and chaos.
"I saw a car flying through the air, right off the bridge," she said. "It looked like as if Superman had thrown a car right off the bridge. It was just flying down."