A Chester County couple and their two sons were found dead Sunday afternoon in what police say was a murder-suicide.

Relatives identified the victims Monday as Deepak Kulkarni, 50, his wife, Arti Adya Kulkarni, 47, and their sons Shubham, 14, and Sharvil, 7.

All four died from gunshot wounds, the county coroner said in a statement Monday. West Whiteland Police Detective Scott Pezick said it was unclear who was responsible for the killings.

Police were called to the family’s home on Mountain View Drive about noon on Sunday, when Arti Kulkarni’s siblings grew concerned that they had not heard from her in several days.

Her relatives, who live in New Jersey, drove to the townhouse the family rents in a subdivision behind the Exton Regional Rail train station, police said. When their knocks on the door went unanswered, they called police. Officers were able to get inside using a garage-door opener from one of the family’s vehicles and found the family dead in the basement.

District Attorney Deborah Ryan said in a statement Monday that her sympathy “goes out to the family for their unimaginable loss.”

“This is a tragedy beyond comprehension because two children and both their parents are dead. These were members of our community,” Ryan said. “We will do everything in our power to learn why this horrific incident happened.”

Neighbors said the family had lived in the development for about two years.

Kulkarni worked as a software analyst at Education Management Systems, according to his LinkedIn profile. His wife was also in that field, working as an application developer, most recently for the University of Pennsylvania.

Karen Stankiewicz lives two doors down from the couple, and said news of their deaths stunned everyone on the block.

Kulkarni, she said, took daily walks to stem the monotony of COVID-19 quarantine restrictions. He was usually friendly and chatty, she said, but when she last saw him several days ago, she said he seemed “not his usual self.”

On reflection, after hearing the news, Stankiewicz said, she wondered whether something had been bothering him. “It’s just sad, and I just wish we could’ve done something,” she said. “It makes us all want to reach out to our neighbors to see if they need anything.”

Ryan, the district attorney, in her statement urged “anyone who needs support to contact the National Suicide Prevention hotline at 1-800-273-8255.”

West Whiteland police and the Chester County District Attorney’s Office are investigating.