Remember the bombing of the USS Cole off of Aden, Yemen?
It will seem unbelievable, but the instinct of the US captain was SO strong that AFTER the blast when the men scrambled topside to deter follow-up attacks, ammunition EVEN THEN was forbade them.
The ammunition WAS available, and order was given to NOT distribute it to deck gunners.
AND:
The Marines at the gates in Lebanon also did not have ammo, when a suicide truck drove in and blew the place sky-high.
USS Cole Captain wanted to avoid "potential tragedies" immediately AFTER they had come under attack --no live ammo passed out to gunners.
Not quite. The Marines guards at the Beirut barracks had loaded magazines in their ammo pouches, but were ordered not to lock the magizines into their rifles or load a round into the chambers without an order by an NCO. There was also a pair of 90mm recoilless rifle positions atop the multistory barracks building, but the gunners were ordered not to close the breeches of the guns, whose M371A1 high explosive antitank warheads could have taken out the truck as much as 400 meters away from the building.