SAN ANTONIO (AP) — A family of six, including four children between the ages of 11 months and 4 years old, was found dead in the back of an SUV parked in the garage of a San Antonio home, authorities there said Thursday night.

San Antonio Police Chief William McManus said the smell of carbon dioxide was so strong when officers arrived that it “kind of blew everybody back out the door.” He said police had gone to the house for a welfare check requested by the husband’s employer, who had been unable to reach him.

Police at one point suspected the house was potentially rigged with explosives but found none, McManus said. Two cats were also found dead the front seat of the SUV.

“It’s the whole picture. The adults, the children, the pets,” McManus said. “Saying it’s not pretty — there’s no words to describe that.”

McManus said there was evidence “it was not an accident,” and he did not suggest that anyone outside the family was involved. He said the parents were in their 30s but did not disclose their names. The family had military ties, he confirmed to reporters at a Thursday night briefing, but he would not say which branch.

McManus said the family moved into the house in January.