Six workers are missing and presumed dead after a bridge collapsed in the U.S. city of Baltimore. With increasingly treacherous conditions in the darkened, wreckage-strewn waters of Baltimore Harbor, active search-and-rescue operations were suspended about 18 hours after the accident, U.S. Coast Guard and Maryland State Police officials said. The 1.6-mile (2.57 km)-long Francis Scott Key Bridge in Baltimore, Maryland, partially collapsed after a ship hit it on Tuesday. The Baltimore City Fire Department described the collapse as a mass casualty incident.