Authorities say the driver and a passenger in a semi truck were injured after their vehicle plummeted 40 feet off a ramp in downtown St. Louis.

The St. Louis Post-Dispatch reports that the crash took place around 3:30 a.m. Monday at the Poplar Street Bridge, which leads into East St. Louis. The bridge was closed because of the accident but has since reopened for traffic.

Authorities say the driver and passenger were hospitalized in serious but stable conditions. Their names were not released.