HERMISTON -- A seventh sarin-filled rocket caught fire Sunday as a blade sliced through its motor section shutting down processing at the Umatilla Chemical Depot incinerator.

The fire started at 2:06 a.m. after the rocket's deadly nerve agent already had been drained.

The processing line restarted about 4 p.m. Sunday.

Like six previous fires in the last year, the fire started on the second of two processing lines as a blade was making the fifth of seven cuts through the M55 GB rocket, said depot officials.

The fire happened in a heavily reinforced room designed to cotnain any possible explosions.  

Since the fires began in late April, the facility has added fire suppression systems to minimize any damage from a fire. Previous fires, all in 2005, were Dec. 5 and 23, July 29, May 18 and April 7 and 23.

A report released by the Army in February estimated there could be up to 25 more rocket fires nationawide before sites like the Umatilla Chemical Depot are done destroying rockets.

The Umatilla site stores the nation's largest number of M55 rockets, about 91,000 packed with the nerve agent GB, which attacks the central nervous system and can cause seizures and paralysis in the most extreme cases.

All the nerve agents were brought to the depot for storage between 1962 and 1969.