On 16 February, Vice-Admiral Kimpei Teroaka authorized the formation of a kamikaze special attack unit to counter the imminent landings on Iwo Jima.
The kamikaze force consisted of thirty-two aircraft in total, and on the early morning of 21 February, they departed from Katori Naval Air Base, in Asahi, Chiba.
They refueled at Hachijō-jima, and proceeded towards the U.S. naval contingent surrounding Iwo Jima, arriving near sunset.

When the kamikazes arrived, Bismarck Sea was performing routine close air support with the rest of Task Group 52.2.
At the time, the escort carrier task group, having split in two, consisted of Bismarck Sea, her sister ships Makin Island, Lunga Point, Saginaw Bay, Rudyerd Bay, and Anzio, along with a destroyer contingent.
The task group was steaming approximately twenty-one miles (34 km) east of Iwo Jima.
At 17:30, the aircraft on Bismarck Sea were scrambled to deal with incoming planes, which turned out to be friendly.
After recovering her planes, she found it necessary to take on three planes from other carriers and, due to the lack of deck space, to shelter four of her fighters below-decks without emptying their fuel tanks, a decision which would later prove disastrous.
This brought the number of aircraft aboard the carrier to thirty-seven aircraft: 19 FM-2 fighters, 15 TBM-3 torpedo bombers, 2 OY-1 reconnaissance aircraft, and a F6F Hellcat fighter.
At 18:45, the task group spotted the Japanese planes headed for them, when a Mitsubishi G4M made a dive towards Lunga Point.
Gunners from Bismarck Sea shot it down.
At 18:46, five Nakajima B6Ns dove towards Lunga Point.
All four of the kamikazes missed with their torpedoes, and none of them made successful contact with Lunga Point, albeit the third kamikaze's wreckage skidded across the carrier's deck, sparking a brief gasoline fire.
Damage to Lunga Point was minimal, and eleven of her crew were wounded.
There were no fatalities, and she was able to continue operating in support of troops on Iwo Jima.

The fifth plane, however, switched targets, and proceeded towards Bismarck Sea.
At one thousand yards (910 m), it was spotted by, and engaged by gunners aboard Bismarck Sea.
However, despite the heavy gunfire, which damaged the plane, it quickly approached Bismarck Sea from the starboard side at a low angle, which the anti-aircraft guns could not depress sufficiently to fire at.
The plane plowed in under the first 40 mm gun (aft), crashing through the hangar deck and striking the ship's magazines.
At the time of the crash, the aircraft elevator was in operation, and nearly up to the flight deck, when its cables were cut by the kamikaze, causing the platform to drop onto the hangar deck with a tremendous amount of force.
The force of the explosion distributed munitions, including torpedoes, across the deck, and started a fire.
The ship's steering was also rendered dysfunctional by the blast.
The sprinkler system and the water curtains were inoperative, but the fire was nearly under control when about two minutes later, a second plane, likely attracted by the ship's glow against the darkness, approaching from the port side, struck the aft elevator shaft, exploding on impact, killing the majority of the fire-fighting party and destroying the fire fighting salt-water distribution system, thus preventing any further damage control.
The second plane detonated amongst the four fighters which were sheltered belowdecks, and the fighters, with full gasoline tanks, quickly turned the fire into a conflagration, enveloping the entire aft side of the ship.

When munitions onboard the ship began to detonate, and with no firefighting equipment operational, the situation quickly deteriorated.
At 19:00, the crew assembled at their "abandon ship" locations, and the engines were cut.
Captain John L. Pratt issued the order to abandon ship at 19:05.
As the crew abandoned ship, a large explosion, likely from the detonation of the torpedoes within the hangar deck, rocked the ship.
This explosion tore much of the aft-end of the ship to shreds, and she quickly acquired a list
On 16 February, Vice-Admiral Kimpei Teroaka authorized the formation of a kamikaze special attack unit to counter the imminent landings on Iwo Jima. The kamikaze force consisted of thirty-two aircraft in total, and on the early morning of 21 February, they departed from Katori Naval Air Base, in Asahi, Chiba. They refueled at Hachijō-jima, and proceeded towards the U.S. naval contingent surrounding Iwo Jima, arriving near sunset.
When the kamikazes arrived, Bismarck Sea was performing routine close air support with the rest of Task Group 52.2. At the time, the escort carrier task group, having split in two, consisted of Bismarck Sea, her sister ships Makin Island, Lunga Point, Saginaw Bay, Rudyerd Bay, and Anzio, along with a destroyer contingent. The task group was steaming approximately twenty-one miles (34 km) east of Iwo Jima. At 17:30, the aircraft on Bismarck Sea were scrambled to deal with incoming planes, which turned out to be friendly. After recovering her planes, she found it necessary to take on three planes from other carriers and, due to the lack of deck space, to shelter four of her fighters below-decks without emptying their fuel tanks, a decision which would later prove disastrous. This brought the number of aircraft aboard the carrier to thirty-seven aircraft: 19 FM-2 fighters, 15 TBM-3 torpedo bombers, 2 OY-1 reconnaissance aircraft, and a F6F Hellcat fighter. At 18:45, the task group spotted the Japanese planes headed for them, when a Mitsubishi G4M made a dive towards Lunga Point. Gunners from Bismarck Sea shot it down. At 18:46, five Nakajima B6Ns dove towards Lunga Point. All four of the kamikazes missed with their torpedoes, and none of them made successful contact with Lunga Point, albeit the third kamikaze's wreckage skidded across the carrier's deck, sparking a brief gasoline fire. Damage to Lunga Point was minimal, and eleven of her crew were wounded. There were no fatalities, and she was able to continue operating in support of troops on Iwo Jima.
The fifth plane, however, switched targets, and proceeded towards Bismarck Sea. At one thousand yards (910 m), it was spotted by, and engaged by gunners aboard Bismarck Sea. However, despite the heavy gunfire, which damaged the plane, it quickly approached Bismarck Sea from the starboard side at a low angle, which the anti-aircraft guns could not depress sufficiently to fire at. The plane plowed in under the first 40 mm gun (aft), crashing through the hangar deck and striking the ship's magazines. At the time of the crash, the aircraft elevator was in operation, and nearly up to the flight deck, when its cables were cut by the kamikaze, causing the platform to drop onto the hangar deck with a tremendous amount of force. The force of the explosion distributed munitions, including torpedoes, across the deck, and started a fire. The ship's steering was also rendered dysfunctional by the blast. The sprinkler system and the water curtains were inoperative, but the fire was nearly under control when about two minutes later, a second plane, likely attracted by the ship's glow against the darkness, approaching from the port side, struck the aft elevator shaft, exploding on impact, killing the majority of the fire-fighting party and destroying the fire fighting salt-water distribution system, thus preventing any further damage control. The second plane detonated amongst the four fighters which were sheltered belowdecks, and the fighters, with full gasoline tanks, quickly turned the fire into a conflagration, enveloping the entire aft side of the ship.
When munitions onboard the ship began to detonate, and with no firefighting equipment operational, the situation quickly deteriorated. At 19:00, the crew assembled at their "abandon ship" locations, and the engines were cut. Captain John L. Pratt issued the order to abandon ship at 19:05. As the crew abandoned ship, a large explosion, likely from the detonation of the torpedoes within the hangar deck, rocked the ship. This explosion tore much of the aft-end of the ship to shreds, and she quickly acquired a list
USS Bismarck Sea