Air Attacks on the Seikan Ferries

The Seikan ferries linked Aomori and Hakodate and were the main route by which Hokkaido coal reached Honshu. During the Third Fleet's strikes on Hokkaido and northern Honshu on 14-15 July 1945, the ferries and their shore facilities were a principal target; the MIC account names aircraft from the carriers Randolph, Monterey and Bataan as the attackers of Hakodate.

On 14 July ferries were hit at sea, in Hakodate Bay and off Aomori: Matsumae Maru was run aground and burned at about 07:20, Tsugaru Maru sank at 15:10, and Shoho Maru and Hiran Maru sank off Aomori in mid-afternoon. Daiichi Seikan Maru, the only ferry still undamaged at the end of the first day, was sunk on 15 July.

According to the fifty-year history of the ferry service quoted by the MIC, of the twelve ferries in operation ten were sunk or grounded and burned and two were damaged, with 72 injured and 425 dead or missing among passengers and crew. Japanese Wikipedia gives eight sunk, two heavily damaged and burned, two disabled, and 352 dead. In Hakodate itself burial permits show 79 deaths in the city. The loss of the fleet crippled transport between Hokkaido and Honshu for the rest of the war.