At ~ 10:47 AM, Westmoreland 911 dispatched Station 20 (Murrysville VFC) for a Carbon Monoxide (CO) Alarm at a home on Chestnut Street. Station 20 responded with Engine 20 (4 firefighters), with Captain 20 and Lieutenant 20 going directly to the scene. Westmoreland 911 also dispatched Station 610 (Murrysville Medic One) and the Murrysville Police to assist Station 20. Captain 20 and Lieutenant 20 were first on scene, Captain 20 established command, and found that the family had evacuated the home. Station 20 firefighters using SCBA (Self Contained Breathing Apparatus) lead by Lieutenant 20 entered the home, and used 5-Gas Meters to survey the interior. Elevated levels of CO were detected, the firefighters turned off the natural gas supply, and ventilated the home. The ventilation of the home dissipated the CO, and it was determined that the elevated levels of CO had come from a campfire next to home. The fire was extinguished, and the home was safe for the family to reenter. Command 20 returned all Fire/EMS/Police Units to service and station.