According to Monroe News on July 7th:

Students and staff in Monroe High School were evacuated from the building around noon today when contractors working on the north side of the building hit an unmarked gas line, according to Jerry Oley, director of operations.

As of 12:40, Mr. Oley said the gas had been turned off and the scene had been declared safe. The fire department left shortly thereafter, leaving school officials and Michigan Gas Utilities to assess the situation further.

Mr. Oley said the contractors were excavating in the teachers’ parking lot for new drainage when they hit the pipe. The fire department and Michigan Gas were immediately called. The students and staff in the building for Summer Learning Academy, a K-12 program, and the Girl Power camp were relocated to the opposite end of the building before being dismissed to their cars and buses.

Supt. Dr. Barry Martin said as soon as the school received the call there was a leak, the staff followed the established plans and got everyone to the appropriate part of the building quickly and safely. He added that no fumes were reported to be detected in the building.

Steve Pollzzie, one of the administrators for Summer Learning Academy, said the contractors and school officials will work with Michigan Gas to evaluate any damage and determine whether it is safe for school Wednesday. If there are any issues, he says the MPS automatic calling system will identify the households of all Summer Learning Academy staff and students to alert them.