Officials in Atlanta say the collapse of several large steam vaults caused part of one downtown street to collapse, but they still don't know what was behind two other collapses in the same area.
Janet Ward with Atlanta watershed management said three or four large steam vaults that date back to when buildings were heated with steam collapsed under Forsyth Street, causing part of the pavement to tumble down.
She said it was too early to know how much repair work would cost.
Officials still aren't sure what caused part of a Forsyth Street sidewalk to buckle. They also aren't sure why part of Underground Atlanta's plaza gave way just after midnight on New Year's Day.
(Copyright 2009 by The Associated Press. All Rights Reserved.)