Police say they are talking to an elderly woman at the home who neglected to report the deaths of her family members. How and when they died was unclear.
The woman told police that it was her three siblings who had died inside the home and that they had been there for some time. For reasons still unclear to police she failed to report the deaths.
Police say neighbors were totally unaware of the situation inside the home.
"Any senior citizen living alone these days, the neighbors keep an eye on them. But the questions that were posed to them and the answers they received, didn't lead them to suspect that anything was particularly wrong," said Commander Tom Guenther, Evanston Police Dept.
Police say one of them was last seen alive in May of this year, another in April of 2003 and the other in the early 1980s. Their remains were found in different rooms covered in blankets.
Police said they don't believe foul play is involved.