BERKS COUNTY, Pa. (CBS) — Authorities are investigating the mysterious deaths of a brother and sister in Berks County. Four-year-old Brinley Snyder and 8-year-old Conner Snyder, both of Albany Township, died at Lehigh Valley Hospital on Thursday.

The Berks County District Attorney’s Office tells CBS3 the two children were found unconscious Monday by their mother at a home on the 2400 block of Route 143. They were rushed to Lehigh Valley Hospital but were pronounced dead Thursday afternoon.

READ MORE: Teen Victim Speaks Out For First Time Following Racially Motivated Attack Aboard SEPTA Train

Authorities are not yet saying what led to the children’s discovery.

Their causes of death has not been released, but Eyewitness News is told the children died from injuries they suffered on Monday. An autopsy will be performed on Sept. 30, according to Lehigh County coroner’s office.

READ MORE: Supply Chain Issues: How Are Global Shortages Affecting Local Customers?

Eyewitness News tried to speak with multiple people on camera about the loss of the two young lives in their community, but everyone we spoke with refused.

We tried to speak with the mother who found her two children unconscious Monday but a man who claimed to be working on the home said he had no way of contacting her.

The District Attorney of Berks County says this is only the beginning of a lengthy investigation. The DA’s office says they are interviewing everyone who knew the kids.

MORE NEWS: Pennsylvania Supreme Court Rules Mask Mandate For K-12 Schools Remains For Now

The father was not involved in the victims’ lives. Investigators believe this is an isolated incident and there is no danger to the community.