Police, witness: Man fires at commuter train from subway platform in Chicago, no one injured

Members of the Chicago Police Department's SWAT team exit a Chicago subway station where police say a gunman standing on a subway platform opened fire on a commuter train, Thursday, Oct. 9, 2014, in Chicago. The shooting occurred at the LaSalle Street Blue Line station in the city's financial district. Chicago Police spokesman Martin Maloney says officers arrested a suspect a short distance away after the shooting and recovered a weapon. No injuries were reported. (AP Photo/M. Spencer Green) (The Associated Press)

Commuter John Langston talks to reporters at a subway station where police say a gunman standing on a subway platform opened fire on a commuter train, Thursday, Oct. 9, 2014, in Chicago. Langston said he witnessed the shooting, which occurred at the LaSalle Street Blue Line station in the city's financial district. Chicago Police spokesman Martin Maloney says officers arrested a suspect a short distance away after the shooting and recovered a weapon. No injuries were reported. (AP Photo/M. Spencer Green) (The Associated Press)

A Chicago Police officer blocks off a subway station where police say a gunman standing on a subway platform opened fire on a commuter train, Thursday, Oct. 9, 2014, in Chicago. The shooting occurred at the LaSalle Street Blue Line station in the city's financial district. Chicago Police spokesman Martin Maloney says officers arrested a suspect a short distance away after the shooting and recovered a weapon. No injuries were reported. (AP Photo/M. Spencer Green) (The Associated Press)

Police say a gunman standing on a subway platform opened fire on a commuter train in downtown Chicago, though no one was injured.

Chicago Police spokesman Martin Maloney says officers arrested a suspect a short distance away after the Thursday shooting and recovered a weapon.

The shooting occurred at the LaSalle Street Blue Line station, near the Chicago Board of Trade building in the city's financial district.

One witness, John Langston, says the first car of the train was hit. He says four or five shots were fired, and sounded like blows from a sledge hammer. Langston says spent shell casings littered the platform.

Police say the gunman fled after the shooting.

Chicago Transit Authority spokeswoman Catherine Hosinski says passengers were unloaded and no one was reported injured.