Today, in 1969, the USS Enterprise Aircraft carrier exploded killing 27 people in Pearl Harbor, Hawaii.
According to Wikipedia, the fire broke out after a Zuni rocket attached to an aircraft detonated, and spread following further rocket and bomb explosions which blew holes in the flight deck, allowing burning jet fuel to enter the ship's interior. 28 sailors were killed, 314 injured, 15 aircraft were destroyed, and the total cost of aircraft replacement and shipboard repair was over $126 million.