An 82-year-old woman was seriously injured following a head-on collision with a school bus in Stamford.

The incident happened Thursday on Newfield Avenue near Case Road around 12:30 p.m. 

Police say the woman, who was driving a Toyota Camry, crossed the center line and hit the a school bus head-on.

They say the force of the collision pushed her car back onto the other side of the street and that the school bus came to rest at a utility pole.

Police say rescue crews had to cut the roof of the woman's car off to get her out. They say the school bus was coming from Wright Tech High School. The driver and one student suffered minor injuries.

The woman is in critical, but stable condition.

Authorities still don't know what caused the woman to cross the line.