Chemical Explosion This Morning In The Valley

About 250 pounds of an ammonia-based chemical exploded into a large fireball & gas cloud this morning, blowing the roof off of the Universal Propulsion jet-propulsion plant building near Deer Valley Road and Central Avenue. Happy Valley Road was closed between 7th Street & 7th Avenue. It's unclear when it'll reopen, although there's a hope to have employees & residents back to their offices & homes by the end of the day. Most of the evacuated residents lived to the north and east of the plant, which sits on a 144-acre site in far north Phoenix. Universal Propulsion, also known as UPCO, is the only U.S. manufacturer of military aircraft ejection seats, and uses explosives to test products. Evacuated residents can call (602) 876-1011 to find out when they can return to their homes.

credit: William Hermann: The Arizona Republic