Four people are in the hospital after their vehicle and a Metro Transit bus collided Monday morning on Nicollet Avenue in Richfield.

Two of the vehicle's occupants were in critical condition at Hennepin County Medical Center, said Metro Transit spokesman Howie Padilla.

A southbound Metro Transit bus struck the vehicle at the intersection of W. 73rd Street about 7:30 a.m. The impact sent the car into a northbound Metro Transit bus that had been in a separate fender-bender and had stopped on the east side of Nicollet Avenue. The car came to rest on a snow berm, Padilla said.

No one on either bus was hurt, he added.

Metro Transit police and the State Patrol crash reconstruction team are working to determine how the crash occurred.

Traffic on Nicollet Avenue has the right of way at the intersection. Drivers heading east or west on 73rd have stop signs but those on Nicollet do not.

The driver of the car was traveling east on 73rd when the collision happened. It was not immediately clear if that driver had obeyed the stop sign.

Authorities will be reviewing video from both buses and speaking to witnesses as part of their investigation.

Names and ages of those involved have not been released.