Police in Utah believe a father killed his wife and three children and critically injured their 17-year-old son at the family’s home this week then turned a firearm on himself, according to new details released by authorities.

The bodies and the lone survivor were found Tuesday night inside a house in West Valley City, a southwest Salt Lake City suburb, police first reported.

The discovery took place after the mother failed to report to work this week, according to the West Valley Police Department, the lead agency on the case. A concerned relative entered the garage of the home, found a 17-year-old boy critically injured, and notified police.

Arriving officers entered the home and found the 38-year-old mother, and the two daughters, ages 9 and 2, in a bedroom in the upper level of the home, police announced in an update during a press conference Wednesday night. The bodies of the 42-year-old father and the 11-year-old son were located in the living room.

A small handgun, police reported, was found under the father’s body, that police believe was used in the shootings.