An explosion at Northrop Grumman’s remote rocket testing site in northern Utah has destroyed a building.

Officers found no injuries or fatalities in their initial investigation of the wreckage, according to the Box Elder County Sheriff’s Office.

Emergency crews had responded to reports of a loud blast and a dark plume of smoke rising over the rangelands at 7:38 a.m.

It was not immediately clear which building was destroyed and what its purpose was. The aerospace and defense company maintains a large presence in Utah, where it manufactures and tests solid rocket motors.