COLD SPRING, Minn. (AP) — Nearly 40 students were injured Wednesday by a chlorine gas leak in the pool area of a high school where a shooting more than four years ago killed two boys, officials said.

Thirty-six students and a gym teacher were taken to hospitals from Rocori High School, Mayor Doug Schmitz said. At least one other person was injured.

Twelve students and the teacher were admitted to St. Cloud Hospital to be monitored overnight, hospital spokeswoman Jeanine Nistler said. None was seriously ill, she said.

Rocori High was the site of a deadly shooting 4 1/2 years ago. John Jason McLaughlin was 15 when he took a gun to school on Sept. 24, 2003. He is serving a life sentence for killing Aaron Rollins, 17, and Seth Bartell, 14.