From the 1.1.2 Patchnotes:

Particle Cannons can no longer be permanently disabled.

Well, someone died while he was using the Cannon, and now the cannon can't be used anymore. It's been 2 hours since we've been able to use it.

Any chance we could get the Particle Cannons from stopping being usable if people die while they're using them? Would be nice to have a way to fight Imps when we're being camped.