By Molly Daly

PHILADELPHIA (CBS) – A motorist is under arrest after police say he hit two police cruisers while officers were investigating an earlier accident in West Philadelphia in which a pedestrian was struck.

The first accident happened around 2:30, when authorities say a man crossing the street was hit by a woman driving east in the 5600 block of Chestnut Street. She stayed on the scene while police investigated. The pedestrian is hospitalized in critical condition.

Just before 5, police say a drunk driver struck the two police vehicles that were blocking Chestnut street during the accident investigation. He was arrested a short time later, and charged with driving under the influence.