(CNN)The shots were first heard Wednesday morning in the Mattoon High School cafeteria. Angela McQueen, a teacher, and a school resource officer headed to the cafeteria to investigate.
This hero teacher took down a gunman in a high school cafeteria
It was there, inside the large room, that McQueen and the resource officer saw the male student spraying gunfire.
McQueen sprung into action and took down the student as fellow pupils and staff fled, Larry Lilly, supt. for Mattoon Community Unit School District 2, said at a news conference this week. The school resource officer then stepped in and disarmed the student.
"Lives were saved by a quick response of a teacher here," Mattoon Police Chief Jeff Branson said during the news conference. "If that teacher had not responded as quickly as they had, I think the situation would have been a lot different."
One student was struck by gunfire that day, he said. The student was found in the school's parking lot and hospitalized, where he is recovering.
McQueen's mother, Barbara McQueen, told CBS Morning News that her daughter "just took action" because she was worried the student would kill somebody.
"I don't think she even gave it a thought because when she saw the gun, I am sure it was like 'Oh my goodness, we are not going to have another Sandy Hook," her mother said. "She just reacted instinctively."
McQueen, who teaches geometry and algebra, has been at Mattoon High School for 10 years, according to the school's website.
McQueen earned a bachelor's degree in mathematics and physical education at Eastern Illinois University, where she also received a master's degree in educational administration.
In McQueen's biography on the school's website, she was asked to describe why she became a teacher.
She wrote: "I wanted to make the world a better place. There are so many negative influences in the world. I wanted to provide a positive role model as well as try to make math fun and engaging for students."
Police said the student shooter has been taken into custody, and the investigation continues.
Meanwhile, at Mattoon High, students returned to campus this week with balloons to honor the teacher, CBS Morning News reported.
"Mrs. McQueen is like Chuck Norris, basically," the student told the news station. "She's the hero, too."