A gunman wielding an ax and wearing a surgical mask opened fire on Wednesday at a Nashville-area movie theater and was shot dead by police after injuring three people when he doused the theater with pepper spray, authorities said, according to Reuters. The gunman, identified by police as a 29-year-old local man, was pronounced dead outside the backdoor of the theater, which was showing "Mad Max: Fury Road." Police initially gave his age as 51. He had a device in a backpack that was supposed to look like a bomb, Nashville police said. "The only person who was shot was the suspect as he emerged out of the rear door of the single movie theater," spokesman Don Aaron told reporters. Aaron said police officers working an accident scene nearby quickly responded to the reports of a gunman at the theater. One of them entered the theater and encountered the gunman, who fired at the officer. The officer, who Aaron said "may well have saved multiple individuals inside," returned fire and waited for backup. The gunman appeared to be shot dead in a hail of bullets from police when he tried to exit the theater, a witness said. "There was dust flying everywhere," said plumber Sean Oliver, who heard a volley of shots and was able to see the back of the theater. Three people were treated for exposure to pepper spray, including a 58-year-old man who also suffered a superficial wound to his shoulder, likely from the ax, Brian Haas of the Nashville Fire Department told reporters. None of the victims was taken to hospitals. "This could have been a lot worse," Haas said. A backpack that had been strapped to the man's chest was later detonated to eliminate any possible threat. The shooting comes less than two weeks after a gunman opened fire in a movie theater in Lafayette, Louisiana, killing two people and wounding nine others before taking his own life. The incident was on the minds of many in Tennessee. "This makes me want to hug my mother," said Calvin Johnson, 17, who was at a restaurant about 50 yards from the shooting. The Tennessee and Louisiana shootings come three years after 12 people were slain and dozens wounded by a gunman at a cinema in Aurora, Colorado, during a midnight screening of the Batman film "The Dark Knight Rises."