A man fatally shot his 11-month-old infant, his girlfriend and his dog before killing himself, authorities in southwest Las Vegas Valley said.

The Las Vegas Review-Journal reported that the deceased are John Henry Lunetta, 40, Karen Michelle Jackson, 35 and the infant, John Jr. The boy’s first birthday was set for Wednesday.

“This is deranged,” one neighbor told the paper. “He must have snapped.”

Few details about the incident are available. Family members called on authorities to perform a wellness check at about 7:40 p.m. on Monday. Police entered the home and found the bodies, the paper reported. It is not clear how long the bodies have been in the home.

One neighbor asked a responding police officer: “The first think I asked the cop was, ‘How’s the baby? He just looked at me…It’s so sad.”