MaKenna Evans, a 16-year-old sophomore at Santa Fe High School, told CNN she was in geometry class when the shooting started.

First, she heard the fire alarm, she said. When the students got outside, her principal told them all to run.

Evans said students hid behind a building across the street from the school. Her aunt called and told her there was a shooting. (Her aunt's husband is a police officer and he'd told her what had happened.)

Evans' brother picked her up, and she is now safe at home.