At least four people have received financial assistance from the American Red Cross of Montana after losing their apartments to a fire Sunday.  The blaze, which charred the south side of a four-unit apartment building near Rimrock Road and Zimmerman Trail, displaced those individuals.  The cause of the fire is, as yet, undetermined, but initial witness reports said the fire was sparked by fireworks and spread to the building from nearby foliage.  The fire caused about $500,000 in damage to the building.