19 February 1945 US Marines head for Iwo Jima beaches. Photo by AP/US Navy

70 years ago Thursday, US forces landed on the beaches of the Japanese Island of Iwo Jima, engaging in what would become one of the fiercest fought battles of WWII.

US Marines trudging through the black, volcanic sand of Iwo Jima. 1945 Photo credit AP

Operation Detachment, as the assault was officially designated in 1945, would go on for five weeks. The Japanese Army had heavily fortified the island long before the Marines landed. A dense network of bunkers, and artillery positions were supported by 11 miles of underground tunnels.

Graves of the 5th Division Marines on Iwo Jima 23 March 1945. AP Photo

The assault on Iwo Jima resulted in over 26,000 American casualties, with 6800 dead. It was the only US Marine Corp battle where American casualties outnumbered the Japanese.
There were 22,000 Japanese soldiers on Iwo Jima at the start of the battle. 18,844 died either by fighting or suicide. Only 216 were captured. An estimated 3000 Japanese soldiers continued to fight, hide and evade, using the tunnel system and caves on the island. The last of these surrendered almost 4 years after the battle started in January of 1949.

Dogtags at a memorial on Mt Suribachi. Photo credit AP/Greg Baker