Did the US Navy know POWs were aboard ships it sank?

Did the US Navy know American prisoners of war were aboard ships it attacked?

No. Had commanders known, they would probably have tried to board the ships.

The US Navy did not know that the attacked ships carried American prisoners of war. Prior knowledge would probably have changed the response toward an attempt to board the vessel. Incomplete identification and intelligence could therefore endanger prisoners being moved by an enemy. The answer is limited to the information available to the attacking force at the time.