A student shot at least one other student at a Colorado high school Friday before he apparently turned the gun on himself, authorities said.
The student was wounded when he confronted the gunman at Arapahoe High School in Centennial, a Denver suburb, said Arapahoe County Sheriff Grayson Robinson.
Officers found another injured student while securing the school, Robinson said.
A student was taken to a hospital in critical condition, said Jason Dunkel, spokesman for Littleton Adventist Hospital.
Students were seen walking toward the school's running track with their hands in the air. Television footage showed students being patted down.
The school is about 8 miles (13 kilometers) east of Columbine High School in Littleton, where two teenage shooters killed 12 classmates and a teacher before killing themselves in 1999.
Friday's shooting occurred the day before the one-year anniversary of the massacre of 20 children and six educators at school in Newtown, Connecticut.