CHICAGO (CBS) — Chicago Police are looking for a man they say followed another man up the escalator at the Monroe Blue Line Train station and attempted to rob him.

During the incident, the victim was either pushed or fell down the escalator. Due to injuries sustained, the victim was hospitalized and underwent knee surgery, according to police.

The incident happened on Jan. 12 at approximately 9 a.m.

pic1 jb113386 Man Falls Down Blue Line Escalator During Attempted Robbery: Police

Surveillance photo of the offender. (Photo: Chicago Police)

Police said the offender is an African-American male, 30-40 years of age, and approximately 6’3″, 230 lbs.

If you have any information about this incident, please call Area Central Detectives at (312) 747-8384.