Naugatuck fire investigators are trying to determine what caused a house to go up in flames Sunday night.
No one was inside the home when the fire broke out just before 7:00 p.m.
According to fire officials, a driver passing by on the road saw flames at 19 Beecher Street and called 911.
Mutual aid from Waterbury and Beacon Falls Fire Departments were called to assist.
Firefighters were able to contain the fire in 45 minutes, said Naugatuck Fire Capt. James Trzaski .
The cause of the fire is under investigation.
