PONTIAC, Mich. (AP) — Two Macomb County men have been arrested after breaking into a vacant Pontiac school.

The Oakland County sheriff's office says deputies went to the school Thursday morning when interior alarms went off shortly after midnight.

Deputies found a broken window on the first floor. A 17-year-old from Macomb Township and 21-year-old from Eastpointe were found on the roof.

The men indicated to deputies that they were "explorers" of abandoned buildings. One of the men had written his Instagram user-name on a blackboard in the school.

They are charged with breaking and entering and trespassing.

The sheriff's office says the school has been closed for years, but is privately owned.