The semi was hauling almonds when it hit a crash cushion near the I-8 split, spilled fuel into a storm drain and snarled traffic for more than 12 hours.

SAN DIEGO, CA — A semi-truck driver died Tuesday morning after the rig crashed and caught fire on southbound Interstate 805 at the Interstate 8 split in Mission Valley, shutting down most lanes for hours and sending smoke, debris and almonds onto the roadway and nearby businesses below.

The crash quickly became both a fatal investigation and a long cleanup job on one of San Diego’s busiest freeway connectors. California Highway Patrol officers said the driver died at the scene and no other injuries were reported, but the collision blocked traffic deep into the evening, spilled diesel and oil into a storm drain and prompted bridge inspections before all lanes reopened.

Authorities said the wreck was reported just after 6 a.m. on southbound I-805 where traffic peels off toward I-8 near Mission Valley. Investigators said the tractor-trailer appeared to veer off the roadway and strike a crash cushion, the impact-absorbing barrels and barrier system that protect the split from direct hits. Soon after the collision, the truck caught fire and was fully engulfed. A 911 caller told dispatchers the vehicle appeared to explode after impact. By the time officers arrived, CHP Officer Sal Castro said, the big rig was already burning. Thick black smoke rose high enough to be seen from miles away, and the southbound side of the freeway was reduced to a near standstill as emergency crews moved in. Officials later said the driver’s name would not be released until relatives were notified.

What caused the truck to leave the roadway remained unclear Tuesday. Investigators said it was not yet known whether alcohol or drugs played a role, and a toxicology report was pending through the San Diego County Medical Examiner’s Office. Officials said the truck was hauling almonds, and the crash tore open the load, scattering nuts across lanes of the freeway and over the edge of the overpass into the commercial area below. Ray Scheidnes of CHP said the load burst from the trailer and spread widely, mixing the cleanup problem with fuel, oil and the burned remains of the truck itself. CHP also said a combination of diesel and oil entered a storm drain, though authorities said the spill did not affect nearby waterways. Officers said the only confirmed damage beyond the truck itself appeared to be property damage.

The scene below the freeway showed how far the debris field spread. Robert Cabanas, who was getting ready for work nearby, said he heard what sounded like a boom before seeing smoke and almonds falling from above. He said ash and debris began coming down so fast that he went to check on his vehicle. Another nearby worker, Brandi Munday, told local television crews her car had been parked under the overpass when the crash happened. She said she looked up and saw what she described as a mushroom cloud of black smoke and flames on the bridge. When she went to move her car, she said, almonds were still falling around her and onto the vehicle. She also said some pieces dented the car and damaged the engine area, adding to the odd aftermath of a crash that began on the freeway but affected people below it as well.

The shutdown rippled across the morning and afternoon commute in Mission Valley, where I-805 and I-8 funnel traffic between central San Diego and surrounding neighborhoods. The southbound lanes were largely closed for much of the day while firefighters, CHP investigators, tow crews and cleanup workers dealt with the burned tractor-trailer, spilled fuel and scattered cargo. At one point, only a limited portion of the roadway was open, and drivers were urged to use alternate routes through the area, including state Route 163. A woman in the 9000 block of Rio San Diego Drive reported that debris from the crash damaged her parked vehicle below the span, underscoring how the collision affected not just freeway traffic but also the businesses and lots beneath the bridge. Authorities also inspected the bridge for possible damage before restoring full traffic flow.

By late afternoon, crews had made enough progress to restore limited movement through the connector, and by early evening all lanes were back open. NBC 7 reported that Caltrans said the lanes reopened by 6:38 p.m., while Times of San Diego reported the area had fully reopened by about 6:30 p.m., ending a closure that had lasted more than 12 hours. The slight difference reflected updates issued by agencies and news outlets as traffic conditions changed. What did not change was the central fact of the investigation: the driver was the only person killed, and investigators had not publicly identified that person by Tuesday night. CHP said witnesses were still being sought as officers worked to determine exactly why the truck hit the crash cushion at the split. The agency’s next steps include completing the collision investigation, reviewing witness accounts and waiting on medical examiner findings.

Tuesday evening, the fire was out, the wreckage had been hauled away and the route through Mission Valley was moving again, but the crash left behind a fatality, damaged property below the bridge and an investigation that was still centered on the moments before the truck struck the barrier just after daybreak.

Author note: Last updated March 5, 2026.