An explosion Monday aboard an international bulk carrier 1,300 mi. off Cape Cod, Mass., killed two crewmembers and left two more injured, according to the U.S. Coast Guard.

The captain of the 623’ bulk carrier Tamar contacted watchstanders at the Coast Guard command center to report an explosion in the ship’s forward storeroom. The captain initially reported one fatality and three other crewmembers who suffered severe burns. According to a second Coast Guard report, one of the injured crewmembers died later Monday.

The Coast Guard partnered the with New York Air National Guard’s 106th Rescue Wing to respond, and the National Guard launched an HC-130 aircrew with six pararescuers and one combat rescue officer, which arrived on board the Tamar at approximately 9:30 p.m. Monday after deploying from their aircraft with two small boats and advanced life-saving equipment. The Canadian Coast Guard also diverted two warships with physician assistants aboard to respond.

The Marshall Islands-flagged ship was en route to the Azores, Portugal, from Baltimore and continued on its journey once the fire resulting from the explosion was extinguished. The ship’s engineering plant was unaffected and the cause of the explosion is not yet known. The Tamar is owned by Slovenian shipping firm Splosna Plovba.

The Portuguese Coast Guard planned to launch a helicopter to pick up the two injured crewmembers and bring them to the city of Ponta Delgada on São Miguel Island in the Azores.