A fire that gutted a Hobart cafe and forced about 20 people sleeping above it to evacuate was sparked by a faulty bar fridge.
Pilgrim Coffee in a heritage-listed building in the city's CBD suffered more than $500,000 in damage in the blaze late on Monday night.
People staying in short-term accommodation above the cafe were woken by smoke alarms, regional fire investigator Matt Lowe said.
"If those people upstairs didn't have them (alarms), it could have been a lot different," he added.
Pilgrim Coffee owner and award-winning barista Will Priestley said 30 people have been left without work, including staff at a burger restaurant that shares a kitchen with the cafe.
"I could see the smoke billowing out, we knew straight away then it was really serious," he said on Tuesday after being called to the fire overnight.
"All our equipment gone. We'll need a full refit.
"Everyone's quite emotional about it. We were one day shy of our seventh birthday."
Faulty electronics in a fridge started the blaze, with surrounding businesses in the building also suffering damage.