The Los Angeles Police Department has opened an administrative investigation after one of its officers was arrested on suspicion of driving drunk and causing a crash that killed a boy and his parents Tuesday night, reports the Los Angeles Times.

The officer, 26-year-old Edgar Verduzco, was driving a 2016 Chevy Camaro in the southbound carpool lane of the 605 Freeway about 10:30 p.m. in Whittier, CA, when, for reasons still unknown, he steered the vehicle to the right and into the fast lane, where it collided with the rear of a Nissan carrying a mother, father, and their son, the California Highway Patrol said.

The Nissan, which had been traveling about 65 mph, burst into flames, trapping the family inside, the CHP said. All three were pronounced dead at the scene. The boy was believed to be in his teens, CHP Officer Al Perez said. The victims probably won’t be positively identified until at least next week because the bodies are so badly charred, the coroner said.

After colliding with the Nissan, Verduzco’s Camaro continued into the No. 2 lane, where it struck a Toyota Scion before coming to a stop, the CHP said. The driver of the Scion suffered minor injuries.

Verduzco is a military veteran who joined the department two years ago, LAPD officials said. He suffered a broken nose in the crash and was arrested on suspicion of felony DUI causing injuries, authorities said. He is being held on $100,000 bail.