A teenager died in a struggle with staff members two weeks after arriving at a private school that had a state contract to educate juveniles in trouble with the law, authorities say.

Officials of Bowling Brook Preparatory School in Keymar told investigators that Isaiah Simmons III, 17, became enraged Tuesday for no apparent reason and was restrained after threatening to harm students and staff. He lost consciousness as he struggled with staff members, the Carroll County Sheriff's Office said in a statement.

Gov. Martin O'Malley issued a statement Wednesday describing the death as a tragedy that highlighted the need for reform of the state Department of Juvenile Services, which contracts with institutions such as Bowling Brook.

Investigators who arrived at the scene found paramedics treating Simmons for cardiac arrest.

A preliminary examination by the state medical examiner's office did not reveal any apparent injuries that may have led to the death. Blood and drug tests will several weeks to complete, the sheriff's office said.

Felicia Wilson said her son was healthy and did not have any medical conditions.

The Department of Juvenile Services placed Simmons at the residential school after a 2006 conviction for robbery with a deadly weapon, the sheriff's office said. Keymar is 40 miles northwest of Baltimore.

The school did not return a phone call seeking comment.