The King David Hotel is known as one of the fanciest hotels in Israel and is the state of Israel's official accommodation for the world leaders, celebrities, and other VIPs that come to visit. In 1946, the hotel received a different kind of visit. Let's just say it was a blast.
In 1938, the British Mandate move its headquarters to the King David Hotel. After the Black Sabbath in 1946, the Jewish Yishuv sought revenge, and the hotel was chosen.
On July 22nd, a truck delivered the explosives into the hotel, and Etzel fighters dressed up as Arab waiters penetrated the kitchen of the hotel's cafe, and took control of all the workers. The explosives, 350kg altogether, were placed inside of milk jugs, and each jug was pinned to a pillar of the building. On their way out, the fighters were discovered by British officers. In the scuffle, they killed one of the officers and injured the other. The Arab Legion soldiers opened fire on them and injured two of them. One of the injured soldiers eventually died from his wounds.
It isn't completely clear who phoned the hotel to warn about the explosion, or when, but according to the official Etzel statement, at 12:10 they called the hotel, the French Consulate, and the Palestine Post paper, to warn them about the bomb. At 12:37, the whole southern part of the hotel exploded in a tremendous explosion, killing and wounding many.
It isn't clear how many people were hurt from the bombing, but according to British historian Christopher Sykes, 91 people were killed and 45 were injured. 17 of the killed people were Jews, not including the Etzel fighter that was killed prior to the bombing.
As a result of the act, the British enhanced their fight against the Jewish underground units, and the Yishuv leadership, including the Haganah, considered the bombing and other Etzel acts as acts of Jewish terror.
This was the start of a bitter rivalry between the Haganah and the Yishuv leadership and the underground units, the Etzel and the Lehi. A rivalry that eventually resulted in the unfortunate Altalena affair.