A tiny hole in a canister of white phosphorus sparked a fire that destroyed a warehouse at the Pine Bluff Arsenal, officials said Thursday.

Some 7,500 of the canisters, along with the building they were stored in, were destroyed in the June 6 fire.

A report released Thursday found that the fire started in the east end of the warehouse when the volatile compound was exposed to air. The leak was likely from a pinhole caused by oxidation, the report concluded. Heat generated by the exposed phosphorus heated the nearby canisters and ignited the roof framing.

White phosphorus is used in ammunition and to generate smoke screens. The Pine Bluff Arsenal is the Army’s sole producer of white phosphorus ammunition in the Western Hemisphere.

The fire was discovered by security guards shortly after midnight June 5. It was brought under control by 1 a.m. on June 6. No one was injured.

Flare-ups are expected until the cleanup is completed, fire officials have said. White phosphorus is volatile and will catch fire when the temperature hits 90 degrees, so firefighters are monitoring the scene around the clock and cooling the area with water.

The cleanup is expected to start within 30 days, according to a news release from the arsenal.

The warehouse, near the arsenal’s Warbritton Gate, was not part of the ongoing work to dispose of the arsenal’s chemical weapons stockpile.

This story was published Friday, June 24, 2005.