HOLTVILLE, Calif. — Thirteen people were killed Tuesday when an SUV carrying 25 people collided with a semi-truck in Imperial County, authorities said.

The crash happened at 6:15 a.m. on state Route 115 north of Holtville, a city 11 miles east of El Centro. A Ford Expedition was westbound on Norrish Road when it entered an intersection in front of a big rig that was hauling two trailers northbound on SR-115, Chief Omar Watson with California Highway Patrol’s Border Division said.

The big rig collided with the left side of the Ford Expedition. Authorities said it was too early to tell if the SUV stopped at the stop sign.

Authorities say 25 people were inside an SUV when it collided with a big rig in Imperial County Tuesday, killing 13 people.

Twenty-five people between the ages of 15 and 53 were inside the SUV, Watson said. Twelve people, including the SUV driver, died at the scene and one person died at a hospital.

The driver of the big rig was taken to Desert Regional Medical Center to be treated for moderate injuries, Watson said.

Roberto Velasco, director of North American affairs for Mexico’s Foreign Relations Department, said Tuesday on Twitter that at least 10 of those killed were identified as Mexican citizens. No identities have been released and the cause of the crash is still under investigation.

El Centro Regional Medical Center staff initially reported 15 deaths caused by the crash. Judy Cruz, managing director for the hospital’s emergency department, said seven patients were taken to El Centro Regional Medical Center, where one died. Two patients were taken to Pioneers Memorial Hospital in Brawley.

Six victims were taken to hospitals in San Diego, including an adult female and teenage male who were flown to Scripps Mercy Hospital. Four patients were being cared for at UC San Diego Health’s Hillcrest trauma center, spokesperson Jacqueline Carr said.

All lanes of northbound and southbound SR-115 were closed at Norrish Road as authorities investigated.