Five fire trucks and about 16 firemen from the Cumberland County Fire Department were kept busy for about two and a half hours this afternoon battling a brush fire that spread over several acres.  The fire broke out at an abandoned house on Byrd’s Creek Drive off Highland Lane this afternoon and, because of low humidity, began spreading rapidly.  Firefighters worked to contain the fire as much as they could before several acres went up in flames.  Two dozers were brought in by the Forestry service to dig fire-lines around the blaze to prevent it from spreading farther. To complicate matters, several 20-gallon propane tanks were scattered around and began exploding during the fire. No injuries were reported.