The fire particles are a simple, yet important particle for ATF: Deep Six events. They usually are in use if a tank/artillery is firing or a building has been impacted by a bomb and
is now burning out.
A list of the uses of them are:
Fort Shad - Artillery & blown up buildings
July 21st Event - MEB Artillery and Soup Shark and post office.
Railtank - Railgun and turret.
(Mid-air explosions not included)
USS Winfall - Hit turrets and firing turrets.
July 4th Event - JD (Justice Department) and Pharmacy
US Bomber - Wings and body.