Limitations imposed by the 1922 Washington Naval Treaty prevented the class from being completed as designed. However, the treaty had a limited allowance for hulls already under construction to be converted into aircraft carriers. "Amagi" and "Akagi" were both intended for conversion, but an earthquake damaged the hull of "Amagi" so extensively that the ship was scrapped. "Akagi" was reconstructed as an aircraft carrier and served with distinction as part of the "Kido Butai" during the Second World War, participating in the Japanese attack on Pearl Harbor before being sunk at the Battle of Midway.