The fire broke out Sunday afternoon at Johnson’s True Value and Bell’s IGA in Calais. The fire department received help from several surrounding towns, including fire crews from Canada.

WCSH-TV reportwed (http://on.wcsh6.com/1LRRjBn ) one of the firefighters was taken to a hospital for heat exhaustion, but no critical injuries were reported.

Both businesses plan to assess the damage and decide when they will reopen.

The cause of the fire remains under investigation.