Puerto Rico trench, North America, North Atlantic;
Summary
Picked up 9 out of 10 OBSes. One OBS (#9; middle one north of the trench) did not respond despite 4 hours of efforts. Lithium battery pack of OBS #5 exploded on board ~36 hours after recovery following a slow undetected fire in the battery sphere. No injuries and no damage. Only partial data recovery from the remaining instruments because of programming error of the instruments prior to deployment.
