The fatal fire in Sheffield, Massachusetts that left five dead is being investigated as a murder-suicide, according to Berkshire District Attorney Andrea Harrington.
One of the five victims of a house fire in western Massachusetts was identified by her employer as a patent attorney with an Albany, New York firm.
Harrington identified the other victims as Wilbur's 41-year-old husband Luke Karpinski, and their 7-year-old twins and 3-year-old child.
Hoffman Warnick said Thursday that Justine Wilbur "died with her family" in the Wednesday morning blaze in Sheffield.
The firm said Wilbur "was smart, knowledgeable, dedicated and hardworking," a devoted mother and a true friend.
The DA says the incident was determined to be a murder-suicide, and said Karpinski was suspected as the assailant.
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Authorities say the mother was found separately from the other four killed in the fire, and the incident remains under investigation.
Harrington says the fire in Sheffield was reported just before 8 a.m. Wednesday, and the home was fully engulfed when fire crews arrived.
Harrington called the investigation "complicated," and causes of death were not available on Thursday.
The superintendent for the Southern Berkshire Regional School District said "while details are still emerging about the fire, our focus is on supporting our students, teachers, families and community members.”
The bodies of the family were brought to Boston to determine the manner of death, and officials said there is no reason for the public to feel unsafe while they investigate the incident.
The Associated Press contributed to this story.