Reports indicate a resource officer at Maryland’s Great Mills High School “exchanged gunfire” with the attacker Tuesday morning to end the threat.

Breitbart News reported news of the shooting and indicated that St. Mary’s County Sheriff Office was on scene and FBI and ATF agents were en route.

Injuries are reported as three, including the shooter.

ABC 7’s Brad Bell tweeted:

NBC’s Christina Ginn tweeted:

WTOP reports that the shooting began with a single shot fired at “a girl in the hallway” at the start of the school day at Great Mills High. It is unclear how many more shots were fired as “students and staff” alerted the resource officer. That officer then moved to engage the shooter, ending the threat.

WSAV/WRC reports that two students were reportedly injured and are hospitalized in critical condition as a result of the shooting. They confirmed that the shooter was also in critical condition after being engaged by the resource officer.

UPDATE: CNN reports that St. Mary’s County Sheriff Tim Cameron says the Great Mills High School shooter succumbed to his injuries after being engaged by the resource officer.

AWR Hawkins is an award-winning Second Amendment columnist for Breitbart News, the host of the Breitbart podcast Bullets with AWR Hawkins, and the writer/curator of Down Range with AWR Hawkins, a weekly newsletter focused on all things Second Amendment, also for Breitbart News. He is the political analyst for Armed American Radio. Follow him on Twitter: @AWRHawkins. Reach him directly at awrhawkins@breitbart.com. Sign up to get Down Range at breitbart.com/downrange.