The following day, his own Zero having been destroyed, Nishizawa and other pilots of the 201st Kokutai boarded a Nakajima Ki-49 Donryu ("Helen") transport plane and left Mabalacat on Cebu in the morning, to ferry replacement Zeros from Clark Field on Luzon.
Over Calapan on Mindoro Island, the Ki-49 transport was attacked by two F6F Hellcats of VF-14 squadron from the fleet carrier USS Wasp and was shot down in flames. Nishizawa died as a passenger, probably the victim of Lt. j.g. Harold P. Newell, who was credited with a "Helen" northeast of Mindoro that morning.
Upon learning of Nishizawa's death, the commander of the Combined Fleet, Admiral Soemu Toyoda, honored Nishizawa with a mention in an all-units bulletin and posthumously promoted him to the rank of lieutenant junior-grade. Nishizawa was also given the posthumous name Bukai-in Kohan Giko Kyoshi, a Zen Buddhist phrase that translates: "In the ocean of the military, reflective of all distinguished pilots, an honored Buddhist person." Because of the confusion towards the end of the Pacific war, the bulletin's publication was delayed and funeral services were not held until December 2, 1947.