At approx 1645 hrs Chief 10 was returning to Calvert County along Rt-231 in Charles Co when he noticed a large column of black smoke coming from the Benedict area. As Chief 10 was heading towards the smoke Calvert units were alerted for working fire at a restaurant in Benedict, at the same time Chief 10B was in Calvert Co in the area of the industrial park and saw the same column. Both Chiefs arrived on scene with the first arriving units from Benedict and assisted Hughesville E22 with connecting their lay out which was picked up by St.Marys E23. Charles Chief 2A had the command and announced exterior operations only, Calvert TWR 2 set up its ladder pipe while E71 was asked to draft out of the Patuxent River for a secondary water supply. Units operated for several hours to extinguish all the hot spots. Chief 10B remained on scene with Hughesville PA29 providing EMS standby for the fire.