Authorities believe that a Sheffield man killed his wife and three children before setting their house on fire and killing himself.

Berkshire District Attorney Andrea Harrington says that it's believed the Wednesday morning blaze in Sheffield was a circumstance of a murder-suicide. Harrington says Luke Karpinski apparently killed his wife, Justine Wilbur, and their 7-year-old twins and 3-year-old before killing himself.

The fire in Sheffield was reported just before 8 a.m. Wednesday, and the home was fully engulfed when fire crews arrived. Harrington did not disclose a weapon that may have been used in the killings or the causes of death. She also did not comment on whether the victims were dead before the fire started or exactly how it was set.

The Berkshire Eagle is reporting .A statement from the law firm where Justine Wilbur worked says her colleagues are facing:

"grief and immeasurable sorrow. Justine was a talented attorney who joined our team in 2017 after having built a reputation both domestically and internationally as a patent expert," said the statement from Hoffman Warnick Intellectual Property Law. Her work was both meaningful and challenging, having encompassed topics ranging from cancer treatment and nanotechnology to advanced materials., Justine was smart, knowledgeable, dedicated and hardworking. She was a devoted mother to her wonderful children, and a true friend to everyone in our firm, it said. "We are each devastated by loss and extraordinary sadness, but are comforted and grateful for having shared Justine's infectious spirit and energy. We pray for her family and those who loved her."

At this point, there is no indication from the District Attorneys office bout what might have motivated Karpinski to kill his family.