Police in Chester have seen just about everything. But they’re not quite sure what to make of what happened inside an apartment in the 900 block of Keystone Road.

What they know is this: Whatever happened, it wasn’t good.

They also know this. Four people are dead as a result of something that happened in the second-floor apartment. But just what did happen remains a mystery.

Police were called to the scene Saturday night by a relative of one of the victims who became concerned after not hearing from the woman who lived at the apartment.

What police found inside was mystifying. The bodies of four people were discovered, three adults and a child. The bodies were found in different rooms. There was no sign of trauma on the bodies. There was no evidence of a forced entry into the apartment, nor of a struggle inside the tidy residence.

In these instances, the first thing looked at is usually a problem with carbon monoxide. But fire officials quickly ruled that out.

What caused the deaths is at this point is undetermined. Results of autopsies on the four bodies is due later today.

In the meantime, police simply are ruling the deaths as “suspicious.”

A mystery? Absolutely.

In the meantime, a chill has gone through the neighborhood as those who live nearby wonder just what happened inside that apartment.

The answer could come later today. And not a minute too soon to ease the minds of relatives, police and neighbors who are left to simply shake their heads and wonder what took the lives of four people.