CHICAGO (STMW) — No one was injured Saturday afternoon when a backup generator backfired and blew out a window at a building on North Wacker Drive downtown.

Firefighters responded about 2 p.m. to the building at 1 N. Wacker Dr., according to Fire Media Affairs.

According to dispatch reports a backup generator backfired and shattered a window.

No one was injured and the cause of the mishap was under investigation, according to Fire Media.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)