An off-duty Los Angeles County Fire Department captain was killed this week and a Caltrans worker was injured in a collision on the northbound Antelope Valley (14) Freeway in Santa Clarita.

A Jeep and a Caltrans vehicle collided just south of Sand Canyon Road about 11:15 a.m. Wednesday, California Highway Patrol Officer Moises Marroquin said.

According to the CHP accident report, the Caltrans vehicle—a GMC3500 with a dump truck bed that was part of a sweeper operation—was traveling within the northbound center median when it was rear-ended by a Jeep.

The Jeep driver, an Agua Dulce resident identified as Capt. Michael Shepard, 63, of Fire Station 132 in Canyon Country, died at a hospital. Authorities at the scene covered Shepard’s body with an American flag. Sheppard, a former Army paratrooper, was planning to retire next year.

“”Everyone that knows him says he’s just a nice guy…a good guy,” said his brother, Steve Sheppard.

The driver of the Caltrans vehicle suffered moderate injuries and was taken to Henry Mayo Memorial Hospital for treatment, according to the CHP.

The crash shut down the carpool and number one lanes until about 7 p.m. Caltrans reported about 3:45 p.m. that the closures had caused an eight-mile, 90-minute traffic backup.