Investigators probing the March collapse of the Francis Scott Key Bridge in Baltimore said in a preliminary report Tuesday the cargo ship Dali experienced an electrical blackout about 10 hours before leaving the Port of Baltimore while undergoing maintenance. The report issued by the National Transportation Safety Board says the power outage was caused by a crewmember mistakenly closing an exhaust damper, causing the ship’s engine to stall. The ship lost power again and crashed into one of the bridge's supporting columns shortly after leaving the port on March 26, which brought the bridge down in seconds. The agency says a full investigation could take a year or more, the agency said.
