One person was killed and another sent to the hospital after police shot a man armed with a knife Saturday morning at the Westminster at Lake Ridge senior living home in Woodbridge, Virginia.

Prince William County Police Chief Peter Newsham detailed during a news conference that officers were called to a privately-owned apartment at the senior living community just before 10 a.m. for a man in distress who was armed with a knife and wanted to harm himself.

Once on the scene, two responding officers were confronted by the man, 26-year-old Joseph Cassell, who proceeded to lunge at officers with a knife after disregarding orders to cease, according to police. Officers discharged their firearms during the initial confrontation.

According to Newsham, officers fired again after Cassell began stabbing a 91-year-old woman who lived inside the apartment. Preliminary findings later revealed she was Cassell’s grandmother.

The man was pronounced dead at the scene after life-saving measures were administered by officers.

The grandmother, who sustained stab wounds and a gunshot wound, was transported to an area hospital. She remains in stable but serious condition, Newsham said.

A second woman was found inside the apartment but she didn’t sustain any injuries. The responding officers weren’t injured.

“This is tragic,” Newsham told reporters during a press briefing. “For the grandmother, for the mother of this 26-year-old who lost his life. And then we also have two officers involved and the last thing in the world that these officers wanted to do when they came to work today was be in this type of an incident.”

Newsham said it remains unclear how many bullets were fired during the confrontation, and that an investigation would be overseen by the regional Critical Incident Response Team. A full report would be released to the public in the future.

The police chief said that no calls had been made to the Prince William Police Department about the pair prior to the Saturday shooting.

Both officers — one described as a veteran and the other with 18 months on the job — will be placed on routine administrative leave for the duration of the investigation.