Authorities are investigating the cause of an explosion aboard a cargo ship that was leaving the Port of Baltimore when it issued a mayday call

The main channel used by cargo ships to enter and exit the Port of Baltimore was closed off Tuesday as the Coast Guard sought to probe the cause of a Monday evening explosion on board a coal

An explosion rocked a cargo ship carrying coal in Baltimore, causing a fire and sending a stream of smoke into the sky but leaving no injuries, authorities said Monday evening.