DERBY, Kan.  -  Fire crews were called to a home in Derby Monday afternoon.  It happened just before 3:00 p.m. in the 11000 block of East Fireside, near 63rd street south and Greenwich.  Investigators say there was a small explosion reported, possibly in the basement.
     Three adults and one child were in the home at the time, and all were able to get out of the house safely.  There were no injuries.  The home sustained damage to the basement as well as the roof.  Immediate damage estimates were not available.  The cause of the fire remains under investigation.