Died as a prisoner of war.
From Find a Grave:
2nd Lt. Edward M. Grimes was held as a POW in the Philippine Islands. In December 1944, he was boarded onto the Oryoku Maru for transport to Japan. The ship sailed on December 13th and came under attack from American planes on December 14th. As evening approached, the attack was called off. The next day the planes returned and continued the attack. When the pilots saw the large number of men climbing from the ship's holds, they realized the ship was carrying POWs and called off the attack. After the POWs were off the ship, the attack resumed and the ship was sunk by American planes at Subic Bay, Philippine Islands, on December 15, 1944. The surviving POWs were boarded onto the Enoura Maru which sailed on December 27th and reached Takao, Formosa, by the New Year. While docked it was bombed by American planes on January 9, 1945, killing many of the POWs. The surviving POWs were boarded onto the Brazil Maru which sailed on January 13th and reached Japan on January 29, 1945. He died at Moji Military Hospital in Japan. His remains were cremated and placed in a large urn. After the war, since most of the ashes were those of British POWs, the urn was interred at Yokohama War Cemetery.