The report came in around 2:40 p.m. Monday about a townhouse on the 600 block of West Boxborough Drive.
The building was engulfed in flames and later collapsed.
Upon arrival, firefighters quickly struck the second alarm and the blaze began spreading to neighboring homes in the area.
Authorities are investigating reports that someone at the party blew out candles, and accidently threw them into a trash bag near a gas can, which in turn sparked the flames.
Two homes were destroyed and two others were heavily damaged in the fire.
Fire crews brought the blaze under control shortly after 4:30 p.m.
No injuries were reported.