St. Clair R-XIII School District buildings as well as St. Clare Catholic School were placed on lockdown for a short time on Friday morning as a precautionary measure after a loud noise resembling a gunshot was heard near the high school campus.

St. Clair Police Chief Bill Hammack told The Missourian late Friday morning that the source of the “loud noise,” which could have been a gunshot, a vehicle backfiring or something similar, wasn’t known at first, but the situation was deemed safe.

At about 1 p.m., Hammack told The Missourian it appears a blown fuse from an Ameren Missouri transformer in the area may have been the cause. Ameren reported that problem early in the afternoon.

The chief said when a transformer fuse blows, it can create a loud popping sound.

The lockdown was put into effect at 9:18 a.m. and lasted until about 10 a.m., the chief said. He also said it was determined early during the investigation that the noise did not originate on school grounds.

“I heard it,” R-XIII Central Office employee Linda Parks said. “It did sound like a gunshot. Shortly thereafter, Chief Hammack came in and said to lock down all the schools as a precaution.”

The R-XIII Central Office on Bardot Street is about halfway between Highway 30 and East Springfield Road.

Hammack said the noise was heard by several individuals near the Highway 30-Bardot Street intersection. The southeast side of that intersection is part of the high school campus that includes the junior high and Edgar Murray Elementary School.

Both St. Clair Elementary and St. Clare Catholic School are on East Springfield Road near the north end of Bardot Street.

“We talked to several residents on Bardot and Highway 30 and they confirmed they heard the noise,” Hammack said. “... But our investigation determined that everything was safe.”