DECEMBER 16, 2005 - Posted at 7:54 a.m. CST
ST. LOUIS, MO - State inspectors say the broken retaining wall around a southeast Missouri reservoir apparently was made of rocky rubble, not granite, as they had assumed.
The mountaintop reservoir quickly emptied of its billion gallons of water early Wednesday when a section of the wall gave way. The torrent of water ripped through a state park and along the Black River, knocking vehicles off a rural highway and pushing homes off foundations.
Missouri's dam and reservoir safety director says the broken portion of retaining wall, 70 to 80 feet high and about two football fields wide, appears to consist entirely of soil and smaller rock.
The 50-acre reservoir holds water for a hydroelectric plant operated by St. Louis-based Ameren UE.