According to the VPB-111 war diary on fold3.com, Bass was lost while patrolling the Makassar Straits. That seems a long way from Singapore. The link to the War Crimes in Singapore mentions that 4 B-29 crewmen were killed earlier in the year. Those four were from the B-29 42-65226 which was lost during a raid on Singapore on January 11, 1945. They were captured and beheaded on February 10, 1945.
http://darkandbizaarestories.blogspo...9-crewmen.html
The crewmen:
Ellis, Samuel B., Jr (S/Sgt) - Left Gunner
http://www.abmc.gov/search-abmc-buri...0#.VPDoSNTN9wA
Osterdahl, Carrol N. (1st Lt) - Navigator
http://www.abmc.gov/search-abmc-buri...2#.VPDojdTN9wA
Heiss, Edward (1st Lt) - Bombardier
http://www.abmc.gov/search-abmc-buri...9#.VPDovdTN9wA
Yowell, Robert W. (1st Lt) - Radar Operator
http://www.abmc.gov/search-abmc-buri...7#.VPDo59TN9wA