What sank the cruiser submarine Surcouf?

Did a B-24 sink Surcouf after reporting a large submarine in the same area?

Possibly, but the evidence is inconclusive; a destroyer collision or another accident also remains plausible.

The submarine disappeared without evidence strong enough to establish a single explanation. The aircraft report, possible destroyer involvement, and accidental loss remain competing theories, so the answer preserves the uncertainty rather than choosing one.