The smoke detector that saved the lives of six people in Gwinnett County Tuesday was installed by firefighters three years earlier as part of an effort to ensure more residents have smoke alarms.

Gwinnett County Fire Chief Russell Knick said firefighters installed the smoke detector in Dec. 2016 at a house on Dogwood Street in Duluth that caught fire early Tuesday.

The residents, who were asleep when the fire started in the basement of the one-story house, were awakened by the smoke detector’s alarm, Capt. Tommy Rutledge said. The home is a total loss and the cause of the fire is undetermined, he said, but the five adults and one child escaped unharmed.

Lt. Aaron Blackwell, whose crew installed the smoke detector and relieved the firefighters who responded to the initial call, said the residents were appreciative Tuesday, despite the loss of their home.

“They had smiles on their faces,” he said. “It’s very satisfying.”

The residents, who have been displaced, are being helped by the Red Cross. They could not be reached for comment.

Gwinnett County had installed about 3,000 smoke detectors annually through a 12 Days of Christmas program that started in 2015 said Knick, the chief. Last year, the county expanded the smoke detector giveaway and created the Prevention 365 program to expand the giveaways year-round. In 2019, about 5,000 residents got smoke detectors through the program said Matthew Phillips, the assistant fire marshal in charge of fire education and investigations.

Knick said there were several instances where the county’s efforts allowed people to have working alarms in their houses that alerted them to a fire, but that the county didn’t track exactly how many.

He called it the “ultimate” success.

“You have seen those calls where three or four people are deceased because they didn’t have a working smoke alarm,” Knick said. “These people walked away this morning just fine.”