WTVD reports the call came in at about 6:30 a.m. Friday morning. Students that were already on buses were transported to the Lowes Foods across from the school.
Rowell said deputies swept the school but found no evidence that any shots had been fired.
"We think it's going to be related to that faulty mechanical equipment", Rowell said.
There was a reported active shooter situation at a North Carolina high school, although officials now say they believe it was a false alarm caused by a malfunctioning water heater that made a noise that sounded like a gunshot. "Law enforcement responded immediately and it has been determined there is no shooter and no weapon".
Commissioner George Brown told WECT that there is a piece of equipment at the school that has been malfunctioning recently and sounds like gunfire when it makes noise.
Earlier this morning, a parent told WWAY he received a call from the school district this morning that all schools on the eastern side of the county are on lockdown.
WECT TV reported that a local commission said no active shooter has been identified.
According to the school website, school begins at 8:30 a.m.
Topsail High School is about 105 miles southeast of Raleigh.