A fire that killed two people and injured three firefighters in Lancaster City on Monday has been ruled accidental, authorities said. Flames broke out in the basement of a row home located along the 200 block of East Madison Street around 4 a.m.

Pauline Stone, 39,  and her niece 6-year-old Leilani Roman both died in the fire.

Investigators may never know what sparked the blaze.  Extensive damage to the structure made finding out what exactly caused the fire extremely difficult, said Trooper Dustin Shireman, a state police fire marshal.