Two Marines were killed Wednesday evening and two others were seriously injured when two transport vehicles crashed along southbound Interstate 15 in north San Diego, according to the California Highway Patrol.
One of the armored trucks had broken down earlier in the evening and was being towed by the other, said Maurice Luque, spokesman for the San Diego Fire Department.
Marines from the broken truck had piled into the working vehicle, which was overloaded, and some were riding on top, he said.
The driver apparently lost control near West Bernardo Drive while changing lanes about 7:30 p.m., officials said.
The fatally injured men, ages 22 and 20, were ejected and tumbled off a bridge and down a 100-foot embankment into a construction site, Luque said.
One of the transport vehicles was left dangling from the bridge.
The Marines were heading to Miramar Marine Air Corps Station from the base at Twentynine Palms, CHP officials said.
The CHP is investigating the accident.