Blast rocks school under construction in Missouri City

MISSOURI CITY, TX It happened at High School Number 11 on Sienna Parkway in Fort Bend County late last night. Residents reported hearing an explosion coming from the site, followed by a huge ball of fire.

"What that was caused by was a huge propane cylinder," said Rob Baker with the Fort Bend County Fire Marshal's Office. "A propane cylinder had a BLEVE (boiling liquid expanding vapor explosion) and it was impinged on by an existing fire that caused the BLEVE and it was the large fireball that everybody saw."

Investigators say the fire caused an estimated $50,000 in damage. No one was hurt.