A suspicious smell at 9:30 Friday morning caused an evacuation at Martin Elementary School in Flowery Branch. But by 10:30 a.m., a sweep of the building by Hall County Fire officials found no cause for alarm.

Principal Tamara Seymour said a teacher reported a suspicious smell in her classroom and alerted her. After inspecting the cause of the smell with the school custodian, Seymour said she called the fire department to confirm whether the smell was actually natural gas.

She said once the alert was issued, it took 1 minute, 55 seconds to evacuate all 800 students and 105 employees at the school, located at 4216 Martin Road.

"We went to the room and evaluated the heating unit ... and it was definitely a different smell than anything we’ve ever experienced," she said. "Another concern was that the heating unit was not (supposed to be) on, and because it was on was another reason for me to be alarmed."

Hall County Fire Marshal Scott Cagle said crews responding to the scene said they did not find any sign of a gas leak. By 10:30 a.m., students were filing back into the school.