A gunman killed a student at an Oregon high school and was later "confirmed deceased," authorities said.

SWAT teams surrounded Reynolds High School after receiving a report of a shooting shortly before the beginning of the school day Tuesday. Reynold High School is located just outside of Portland. The school year had been scheduled to end Wednesday.

"We are still checking the building," Sue Strickland, police records specialist for the Troutdale police, told USA TODAY. "We have about 40-50 units out there. We have several SWAT teams in the building right now and they are checking to make sure that they've got things under control. A semi-automatic weapon was used."

Agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives are heading to Reynolds High School to assist in the investigation, the ATF said Tuesday on its Twitter feed.

Reynolds High includes grades 9-12, and has more than 2,800 students.