Savage mentioned it earlier, but details were still sketchy. Yakima Herald reports:

A SWAT team entered the man’s home and found four people dead. They were found in a different structure than the one the suspect was inside during negotiations, Salisbury said. Police searched 11 structures on the property.

The suspect they were negotiating with came outside and shot himself, bringing the death toll to five. Komo reports:

The gunman had called 911 to say he shot and killed his family near the town of Belfair, Mason County sheriff's Chief Deputy Ryan Spurling said. A 12-year-old girl who survived has been taken to the hospital for an evaluation.

A bit more about the family:

The couple who lived in the house were in their 40s and had been married for four or five years... The wife had two teenage sons who were adopted from Russia during a previous marriage. She also had a daughter who was adopted from China.

It's still unclear what exactly happened in Mason County, and why, but as Anna Minard once wrote in The Stranger, mass shootings often begin as domestic violence incidents. Condolences to all.