SAN DIEGO – A 19-year-old pedestrian was hit and killed by a semi-truck Sunday while he was walking along northbound Interstate 15, California Highway Patrol officers said.

Just after 5:30 a.m., the man was on the right shoulder of I-15 south of Carroll Canyon Road when he walked into the traffic lanes for unknown reasons, CHP Public Information Officer Salvador Castro said. When that happened, the man was struck by a driver in a white Freightliner big rig.

The result left the man with major injuries. He died at the scene, according to Castro.

Investigators closed the right lane of northbound I-15 for two-and-a-half hours while crews were on the scene. In that effort, the driver of the Freightliner stayed put to speak with investigators.

Castro said the victim’s name is being withheld pending notification of next of kin. A toxicology report also will be conducted to see if drugs or alcohol played a role.

The cause of the crash remains under investigation.