Fire broke out in two stores on Main Street in East Hartford late Wednesday night.
Firefighters responded to the Welcome Market at 1517 Main Street just before midnight and encountered heavy fire in the basement and first floor, according to fire officials.
The flames spread to the Dollar World store next door.
Both businesses suffered significant damage and won't be able to open on Thursday, fire officials said.
Fire crews from Hartford, West Hartford and Manchester were called in to help fight the fire.
Firefighters had the fire out in about an hour, fire officials said.
No one was in the building at the time of the fire and there were no injuries.
The cause of the fire is under investigation.