CHICAGO (WLS) -- Chicago police are searching for a driver who took off after hitting and critically injuring man in the Loop on Friday night.

CPD said the hit-and-run crash happened in the 0-100 block of South Michigan Avenue around 9:40 p.m.

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A 66-year-old man went into the street to grab his dog, and that's when a white sedan struck him, police said.

Police said the driver did not stop and continued driving.

The victim, who was knocked to the ground, suffered head trauma, police said. The Chicago Fire Department treated him and took him to Northwestern Hospital in critical condition.

There is no one in custody, and CPD's Major Accident Unit detectives are investigating.

Police did not immediately provide further information.

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