The incident occurred on Ladyslipper Drive in Shrewsbury around 7:30 a.m. Friday, March 19.
Autopsy results on the cause of the deaths are pending, Worcester County District Attorney Joseph Early Jr. said in a news conference.
The surviving father and son are not considered suspects, authorities said.
The identities of the two have not yet been released, pending notification of some family members outside the country, Early said.
The incident is believed to be isolated and poses no threat to the public.
To view a briefing on the incident, click here.
This is a developing story. Check back to Daily Voice for updates.
Click here to follow Daily Voice Worcester and receive free news updates.