A school bus driver was charged with driving while intoxicated Thursday as she picked up students at Leonardtown High School, St. Mary’s County authorities said.

Police received a report about 3:15 p.m. that Ethel Quade Ressler, 67, of Mechanicsville, had been driving her school bus recklessly, St. Mary’s County police said. A police officer stationed at the high school spoke to Ressler, who was parked outside the school and had already loaded 12 students onto the bus, according to police.

The officer smelled alcohol on Ressler’s breath, police said.

Ressler, who police said was arrested after a sobriety test, later threatened to harm herself and was taken to a hospital.

Ressler has been suspended from driving buses for St. Mary’s County Public Schools, a spokesman for the district’s transportation department said. The transportation department is reviewing the case.

Ressler has been driving school buses for the school district for 47 years, the transportation department spokesman said. He said she never failed a drug test and had no record of drunken driving.