A Monday morning structure fire in Madisonville caused substantial damage to the residence. Just after 5:00am Madisonville Fire Department responded to 34 N Harrig Avenue where the house was fully involved. After the fire was extinguished and following a secondary search crews determined no one was in the structure at the time of the fire. An excavating company was called to demolish the structure due to the unsafe conditions. The cause of the fire is undetermined at this time.