OCEANSIDE, Calif. (WKRN/AP) — A U.S. Marine from Middle Tennessee was killed early Monday morning in Southern California when he was struck by a box truck as he was aiding motorists on the side of the highway, authorities said.

The Marine had been helping a couple in an SUV who had been in a crash on Interstate 5 in Oceanside, about 55 miles north of San Diego, at about 3:30 a.m.

The SUV’s driver had lost control and crashed and the vehicle was left in the freeway’s traffic lanes with no lights on, according to multiple media reports. The Marine immediately went to help the SUV’s occupants.

A box truck, driven by a 47-year-old man, crashed into the SUV. The Marine died at the scene and the SUV’s occupants were taken to a hospital.

“He was trying to do the right thing, he was trying to help somebody in need,” according to a statement from the California Highway Patrol. “Unfortunately, the freeway traffic was still moving at the time and the box van came and collided into the vehicle.”

The serviceman, later identified USMC Lance Cpl. Alberto Lucio, of Smithville, Tennessee, was 20 years old and stationed at nearby Marine Corps Base Camp Pendleton.

“Security and Emergency Services Battalion sends our deepest condolences and prayers to Lance Cpl. Lucio’s family,” said Col. John W. Black, commanding officer, Security and Emergency Services Battalion, MCB Camp Pendleton. “Lance Cpl. Lucio performed a noble and selfless act by stopping on Interstate 5 to provide critical aid to a person in need. Lance Cpl. Lucio gave his life in the service of others. His actions epitomized servant leadership and personified the very best in our emergency services personnel. Please honor Lance Cpl. Lucio’s memory through your actions, words and deeds.”

His personal awards include the National Defense Service Medal and the Global War on Terrorism Medal.

California Highway Patrol Sgt. Nicole Pacheco told The San Diego Union-Tribune that the SUV’s driver would be booked into jail on suspicion of multiple felonies after treatment at the hospital.