An active-duty member of the U.S. Navy has been arrested after his truck plunged off a bridge on Saturday, killing 4 people gathered at a festival below. Nine people were also injured in the accident, which police say may be the result of drunk driving. Authorities have identified the truck driver as 25-year-old Richard Anthony Sepolio, who was stationed at the Coronado Island naval base near San Diego. Sepolio was also injured in the accident and is now recovering from major injuries at a hospital. Sepolio’s vehicle went through a guard rail on the San Diego-Coronado Bridge and plunged into a crowd gathered at a vendor’s booth in Chicano Park below. People attending the festival, the La Raza Run, said the truck landed just steps away from where a rockabilly band was playing. “I saw a truck come right off the freeway. It was going so fast it flew over the stage and landed in front of the stage on a tent, a booth that was set up,” one witness, Chase Dameron, was cited as saying by The San Diego Union-Tribune. Four people at the booth were reportedly crushed. California Highway Patrol Officer Jake Sanchez said Sepolio is under suspicion of driving under the influence, causing deaths and injuries.