POUGHKEEPSIE, N.Y. (AP) — Fire investigators continue to search for the cause of a blaze that destroyed an abandoned house in the Hudson Valley, killing four people authorities believe were homeless.

Fire officials in the city of Poughkeepsie tell the Poughkeepsie Journal that Monday's early morning blaze started in a first-floor bathroom of the three-story structure. Firefighters found four bodies inside the gutted home several hours after arriving on the scene around 1 a.m.

The bodies were sent to the medical examiner for identification and to determine the cause of death.

Officials say the home was abandoned years ago and had no electrical services. Fire Chief Mark Johnson says it's not known yet if someone lit a fire in the bathroom to keep warm or if the blaze was started to burn down the house.