SAN ANTONIO -

Accident investigators are looking into what caused a pickup truck to careen off an overpass in San Antonio Friday morning.

It happened around 7:30 a.m. on Loop 410 over Somerset Road.

The truck was headed east on 410 when the driver lost control and suddenly swerved to the left.

The truck hit a guard rail and went airborne, falling in the space between the east and westbound bridges, and rolled several times down an embankment.

The truck landed right side up, but the roof of the cab crushed.

Police say the man and woman riding in the truck were both ejected.

They were taken to San Antonio Military Medical Center in serious but stable condition.