Two volunteer firefighters were killed and two others were wounded when they were lured to a fire in New York state.
The incident happened shortly before 6am on Monday in the town of Webster, on Lake Ontario.
The firemen, who were volunteers, were lured to the scene
Webster Police Chief Gerald Pickering said a person fired at the firefighters as they arrived at the scene of a fire.
The gunman has been named as William Spengler, 62, who appears to have shot himself in the head.
Spengler previously spent 17 years in prison after being convicted in 1981 of killing his grandmother.
His sister is unaccounted for and police fear she may have died in the fire, which engulfed seven houses.
An off-duty policeman passing-by was hit by shrapnel.