LAFAYETTE, La. — Emily Mann and her friend had come into the theater a bit late for the evening showing of “Trainwreck” so they quietly found seats near the top of the small theater. The 21-year-old didn’t notice the man just a few seats down until 20 minutes into the movie when he got up and began firing into the crowd.

“You hear one loud shot and you’re sure that’s not what it is because it would never be that. And then you hear another and another and another and you realize that those aren’t just lights and sounds,” said Mann, speaking to The Associated Press about the brutal killing in a Lafayette movie theater Thursday evening.

John Russell Houser, 59, stood up without a word and started shooting, leaving a horrific scene of blood, bullet holes, spent shell casings, and personal possessions like purses and wallets in a movie theater that was supposed to be a refuge from the stress of daily life.

Amid the tragedy, a tale of heroism emerged: high school English teacher Ali Martin, suffering from a gunshot to the kneecap, made her way to a fire alarm and pulled it. Police say she saved lives, alerting some 300 people in the giant multiplex that something wasn’t right.

Police say Houser then tried to blend into the crowd heading outside as the alarm blared. But he turned back as police officers approached, reloading and firing into the crowd before killing himself with a single shot inside the theater, police said.