This morning a structure fire was reported in Box area 2 on Airport Road alerting Laurel, Delmar, and Sharptown Fire Departments First arriving E4 found fire showing on the C side of the house. Firefighters made entry and encountered heavy smoke conditions and heat, as they advanced their hose line. A Mayday was called as they fell thru the floor in the B/C corner of the house. Additional Firefighters came to their aid and was able to pull them out and the Mayday was cleared. Seaford Fire assisted with a Tanker. Extensive damage was done to the structure and it is under investigation by the DSFM Office. One Firefighter sustained a minor injury and did not need to be transported. Incident was placed under control in roughly a hour.