CNN  — 

Six members of a military family were found dead on Thursday at a home in San Antonio, Texas, in what appeared to be a murder-suicide.

Police discovered two adults and four children dead in an SUV in the home’s garage, San Antonio Police Chief William McManus said at a news conference Thursday night. The family has not been identified, but McManus said the adults, a man and a woman, were in their mid-to-late-30s. The children ranged in age from 11 months old to 4 years old.

Police on the scene in San Antonio, Texas, where two adults and four children were found dead in an SUV in a garage.

The incident does not appear to be an accident, the police chief said. It appeared to be a suicide, McManus said, and the cause of death “appears to be carbon monoxide poisoning.”

Officers arrived at the home Thursday morning to perform a welfare check at the request of the man’s workplace. Officials there said he hadn’t checked in for work like he normally would, since he was working from home.

When police opened the front door, they smelled noxious fumes, McManus said, and retreated.

McManus told reporters earlier in the day that officers also found a “cryptic” note with “military jargon” on the front door. According to McManus, the note, once it was interpreted, said there were “bodies or people inside,” and warned, “Do not enter.”

Police, concerned that the home was “booby-trapped with explosives,” searched the residence with a robot to ensure it was safe. The neighborhood was also evacuated as officers combed the scene.

Police were eventually able to enter the garage, where they found the family dead along with two cats in a basket in the front seat.

“There’s no words to describe that,” McManus said.

The police chief said the family was connected to the military, but did not say which branch. Neighbors told police they never saw any family members, who had just moved to the area in January.