Thick smoke and flames shooting out of the second story of a building that houses Linda Lee Byars Music Store in Marathon closed down U.S. 1 in both directions midday Monday.
Fire units and EMTs responded to the emergency before noon and the blaze was under control before 1 p.m.
It's not clear yet what started the fire and the extent of damage is awaiting reports from the fire department and building owner.
"We’re still under investigation. The fire is out, it was in an upstairs apartment," said Marathon Fire Chief John Johnson. "We’re assisting the owner with any damage on the bottom floor."
There was no fire damage on the bottom floor, Johnson said, only damage caused by water.
Police on the scene reopened Overseas Highway to traffic by 1:10 p.m.