GILLETTE, Wyo. (AP) — Authorities are trying to determine the origin of a blast that shook homes and businesses across northwest Gillette.

The Associated Press reports that Campbell County Sheriff's deputies and city police were sent out across the western half of town at about 1 p.m. Tuesday to locate the source of the blast. The thump shook windows in the Westover subdivision and rattled walls along Second Street.

Investigators have not determined the source of the blast, or whether or not it was inside city limits.