North Hall High School was evacuated this morning after an incident in a science classroom caused smoke.

At about 7:30 a.m., Principal Joe Gheesling learned there was smoke in the science hall at the school and ordered the evacuation, Hall County Schools spokesman Gordon Higgins said. The fire department responded and determined that a hot plate in Room 208 was the source. It appeared the hot plate had been turned off, but there may have been a short in the switch.

Investigators removed the hot plate to confirm the cause.

Students re-entered the building at about 8:20 a.m.