An off-duty Los Angeles Police Department officer was arrested following a fatal crash on Tuesday night that resulted in three deaths.

The crashed happened on the 605 Freeway in Whittier at around 10:15 p.m. As reported at the L.A. Times, the victims were a teenage boy and his two parents from Riverside. They were driving southbound in the fast lane in a Nissan when a Chevy Camaro driven by 26-year-old Edgar Verduzco struck them from behind near Washington Boulevard.

The California Highway Patrol said that the Camaro was driven at a “high rate speed,” and that, after the collision, the occupants of the Nissan were trapped inside as the car erupted in flames. The victims were pronounced dead at the scene by paramedics.

Verduzco was arrested on suspicion of felony DUI. “The officer that investigated the crash concluded that the driver was under the influence after field sobriety tests,” Lieutenant Aaron Knarr of the CHP’s Santa Fe Springs office told LAist.

After being struck by the Camaro, the Nissan crashed into a Toyota in another lane; the driver of the Toyota suffered minor injuries.

The LAPD says it has opened an administrative investigation and will work with the CHP as the agency investigates the crash, reports NBC 4. The LAPD released a statement on the incident, saying it “is particularly troubling when one of our own police officers violates drunk driving laws”:

#LAPD: Chief Beck Statement Regarding Fatal Freeway Crash pic.twitter.com/avvjoNxFsB — LAPD HQ (@LAPDHQ) September 27, 2017

The Los Angeles Police Protective League, a union that represents rank and file LAPD officers, said in a statement that, “if Officer Verduzco is found guilty of what he is accused of, then he should suffer the consequences for his reckless actions.”

The Times reports that lanes on the 605 were closed following the crash, and were reopened by 4 a.m. on Wednesday. Verduzco is being held on $100,000 bail.