WASHINGTON, D.C. — The National Transportation Safety Board announced Thursday that it would launch a second expedition to search for evidence in its investigation of the loss of the cargo ship El Faro, which sank in the Atlantic during a hurricane in 2015.

The loss of El Faro and its 33 crew members has been deemed the worst cargo shipping disaster involving a U.S.-flagged vessel since 1983. Five of the crew, including the captain, had connections to Maine.

The NTSB contracted with the U.S. Navy to find El Faro, which disappeared on Oct. 1, 2015, during Hurricane Joaquin while on a regular weekly cargo route between Florida and Puerto Rico after the captain reported losing propulsion and taking on water.

The last communication between the ship and the mainland was made at 7:20 a.m., according to previously published reports. The cargo carrier lost propulsion and was listing after encountering the hurricane north of San Salvador Island in the Bahamas, the captain said in his request for help.

The crew included 28 Americans and five Poles. Among crew members lost were 53-year-old Capt. Michael Davidson of Windham, a 1988 graduate of Maine Maritime Academy; Michael Holland, 25, of Wilton, a 2012 graduate of Maine Maritime; Danielle Randolph, 34, of Rockland, a 2004 graduate of Maine Maritime; and Dylan Meklin, 23, a 2010 graduate of Rockland District High School and a 2015 graduate of Maine Maritime. Another crew member, Mitchell Kuflik of Brooklyn, New York, graduated from Maine Maritime in 2011.

A key objective of the upcoming mission, which is expected to begin in April and last about two weeks, is to locate the voyage data recorder and to provide investigators with a more extensive and detailed survey of the shipwreck. The exact launch date will be announced later.

“The voyage data recorder may hold vital information about the challenges encountered by the crew in trying to save the ship,” said NTSB Chairman Christopher A. Hart. “Getting that information could be very helpful to our investigation.”

The 790-foot ship was located in about 15,000 feet of water near the Bahamas on Oct. 31. Over the next few weeks, the ship and the debris field were documented with a video camera mounted on a remotely operated vehicle.

Video revealed that the navigation bridge structure and the deck below it had separated from the ship. The missing structure included the mast and its base, where the voyage data recorder was mounted. Neither the mast nor the voyage data recorder was found in the vicinity of the navigation bridge structure. The initial search mission was completed on Nov. 15.

After reviewing the data and video from the initial search, investigators shared findings with NTSB senior leadership, who determined that a return mission to El Faro was warranted.

A search area of about 13.5 square miles will be photo- and video-documented by Sentry, an autonomous underwater vehicle, that will be launched from the research vessel Atlantis, which is owned by the U.S. Navy and operated by the Woods Hole Oceanographic Institution. Sentry can work at depths of nearly 20,000 feet and can be equipped with a wide array of sonar, camera and other sensors.

A voyage data recorder of the type that was mounted on El Faro is capable of recording conversations and sounds on the navigation bridge, which could provide investigators with important evidence as they seek to understand the sequence of events that led to the sinking. In addition, investigators hope to obtain high-quality images of the bridge, debris field and hull.

If the voyage data recorder is located, another mission using a remotely operated vehicle capable of recovering the recorder will be initiated.

A Marine Board of Investigation hearing about the loss of the ship will be conducted by the U.S. Coast Guard beginning Feb. 16. in Jacksonville, Florida.