The arsenal of the Branch Davidians continued to strike out Monday, even as the compound collapsed into an inferno.

Ammunition at the compound exploded as firefighters worked to extinguish the fire.

Waco assistant fire chief R.G. Wilson said some of the ammunition in the compound exploded and hit Waco fire trucks at the scene.

Fire departments from Waco, Bellmead and Northcrest responded to the blaze at the Mount Carmel compound.

Wilson said no firefighters were hurt by the ammunition, and the two Waco fire trucks at the scene only received minimal damage. He said the trucks were fully operational.

Wilson said shell casings, rather than bullets, may have hit the trucks.

Bellmead fire chief James Karl said he could hear popping sounds in the fire that may have also been exploding ammunition.

“There was what sounded like small arms ammunition going off,” Karl said.

He said the sounds also may have come from piles of pressurized canned goods exploding in the heat.

Both chiefs said fighting fires in buildings containing ammunition is very hazardous because the firefighters have no protection from the stray bullets ignited in the flames.

Howell and his followers had amassed a huge arsenal. Included were an estimated four tons of bullets, quantities of black powder and rocket propellants, grenades and anti-tank weapons.

Sources say most of the guns, ammunition and explosives came through two sources: former Hewitt gun dealer Henry McMahon and Branch Davidian Paul Fatta.

McMahon helped Howell buy hundreds of semi-automatic assault rifles and Fatta dealt in guns and ammunition through the Mag Bag, a garage operated by Branch Davidian Woodrow Kendricks.

McMahon moved to Pensacola, Fla., several months ago and has cooperated with investigating authorities. Fatta was away from Mount Carmel during the raid and has been a fugitive since early March, when authorities issued a warrant for his arrest.

Although Howell and his followers bought most of the weapons legally, they converted many to automatic, which is illegal. When agents from the Bureau of Alcohol, Tobacco and Firearms raided Mount Carmel, they had a warrant to arrest Howell for possessing automatic weapons and had a warrant to search Mount Carmel.

Read the Tribune-Herald's 7-part investigative series on the inner workings of the Branch Davidians. Hours after Part Two appeared in print, the ATF raided the group's compound.

Read the Tribune-Herald’s account of the ATF raid on the Branch Davidian compound on Feb. 28, 1993. Four ATF agents and six in the compound were killed in the gunfight.

Read the daily news accounts of the 51-day siege at the Branch Davidian compound near Elk, which began Feb. 28 and lasted until April.

Read the accounts of April 19 and beyond: FBI agents began inserting canisters of tear gas into the Branch Davidian compound in the early morning hours. By noon, it was on fire.