Michael Brandon Hill walked into a suburban Atlanta middle school with a loaded assault rifle on Tuesday afternoon, but no one was harmed, thanks to the efforts of the school’s bookkeeper, Antoinette Tuff.

NPR reports that after Hill entered Ronald E. McNair Discovery Learning Academy in Decatur, Ga., he fired a shot at the ground in the school’s administrative office and began exchanging fire with police outside. By all accounts, Hill was planning on a full-scale firefight with the police, possibly ending in his own death.

Then Tuff began speaking to him. At first, she simply asked the armed 20-year-old his name, and when he wouldn’t respond, she told him her life story. Tuff talked the gunman through the collapse of her 33-year marriage and the “roller coaster” of owning her own business. Tuff assured him that she had pain in her life too.

“He had a look on him that he was willing to kill,” Tuff told ABC News. “He said that he didn’t have any reason to live and that he knew he was going to die today…I knew that if he got out that door, he was gonna kill everybody... I told him, 'OK, we all have situations in our lives. I went through a tragedy myself. It was going to be OK. If I could recover, he could too."

Amazingly, it seemed to work. Tuff talked with the gunman for more than an hour before convincing him to surrender to the police. She asked that he put down his weapons, empty his pockets, and lie down on the ground in surrender, and when police entered the school’s offices, Hill briefly exchanged fire but ultimately surrendered to the authorities.

"I just started praying for him," Tuff told Atlanta’s Channel 2 Action News. "I just started talking to him ... and let him know what was going on with me and that it would be OK. And then [I] let him know that he could just give himself up. ... I told him to put [the guns] on the table, empty his pockets. He had me actually get on the intercom and tell everybody he was sorry, too… I give it all to God; I'm not the hero. I was terrified."

In the end, no one – including any of the school’s 870 students – was harmed in the incident. Currently, Hill is facing charges of assault against an officer, making threats, and illegally possessing a firearm.

Watch Tuff's account of the incident below.