In this Tuesday, Oct. 15, 2019 photo, a memorial to the World War II Battle of Midway is shown on Midway Atoll in the Northwestern Hawaiian Islands. A group of deep-sea explorers scouring the world’s oceans for sunken World War II ships is honing in on sonar readings of debris fields in the Pacific Ocean. A research vessel called the Petrel is launching underwater robots about halfway between the U.S. and Japan in search of warships from the Battle of Midway. (AP Photo/Caleb Jones)