Heavy fog was partly to blame for a two-car crash on the Northwest Side early Thursday morning, San Antonio police said.

The crash occurred just after 2 a.m. on Loop 410 and Babcock Road.

San Antonio police say a driver left a bar on Fredericksburg Road and entered Loop 410, but had some type of accident that caused him to stall out in the middle of the freeway.

A woman driving a silver car then slammed into the stalled car and was forced onto the other side of the highway.

She and her passenger were transported to University Hospital with unknown injuries.

She told police she could not see the stalled out vehicle on the road because of the dense fog.

The driver of the stalled car was booked for driving while intoxicated, San Antonio police said.