Four people were killed Saturday when a truck veered off a San Diego bridge and fell onto a crowd below, crushing four people underneath it, authorities said.
Nine others were injured in the unusual crash as the truck plunged into a park, where San Diego Police said hundreds were gathered for a motorcycle event.
"Anything that size," San Diego Fire Chief Brian Fennessy said, "the outcome is not going to be good."
The crash happened just after 3:30 p.m. while hundreds had gathered at Chicano Park, under the Coronado Bridge, for the La Raza Run, a motorcycle event that includes food, games, music and other events.
The driver of the truck somehow veered of the bridge, plunging down onto the park and the people below.
Officers arrived at the park and asked people to help them push the truck over and clear the area to get ambulances in, Capt. Chuck Kaye of the San Diego Police Department said.
The truck landed on its side and several people at the park helped police push it over to rescue the four people pinned underneath, Kaye said during a press conference.
When the people under the truck were freed, officers tried to render aid but were unable to save them, he said.
The driver of the truck, who was not immediately identified, was arrested on suspicion of driving under the influence, California Highway Patrol officials said. He suffered major injuries.
Another person suffered major injuries, officials said. Seven others suffered minor injuries.
Those injured were not identified, but CHP officials said they all appeared to be adults.