WHEATON, Ill. (AP) — A gunman who took a dozen hostages in a suburban Chicago bank after wresting a gun from a police officer Friday died after shooting himself in the head, police said.

The standoff began around 1:30 p.m. after a Wheaton police officer responded to a call of a hit-and-run accident near the bank. When the officer arrived, the man grabbed the officer from behind, held a knife to his throat and demanded his gun, Deputy Chief Thomas Meloni said.

During an ensuing struggle, the officer was cut on a forearm and the man was able to take the gun and run into the lobby of the Wheaton Bank & Trust, where he ordered everyone to the floor, Meloni said.

Police in Wheaton, about 20 miles west of Chicago, did not immediately release the gunman's identity but said he was about 50 years old.