00-15: Collapse of the Conesville 4B Seven Cell Mechanical Draft Cooling TowerEarly in the morning of July 12, 1998, one of the two seven cell mechanical draft cooling towers serving American Electric Power's (AEP) 780 MW Conesville Unit 4 suddenly collapsed into the cold water basin. Investigation into the cause of the catastrophic collapse and resulting methodology for evaluating the structural integrity of similar towers on the AEP System will be reviewed. Structural upgrades incorporated into the replacement tower design