SAN DIEGO >> Crews doused a small, smoky fire caused by a welder aboard the USS Midway Museum that forced the evacuation of the historic aircraft carrier in San Diego early Wednesday.

The blaze was reported around 5:30 a.m. two levels below the flight deck where construction crews were working overnight, said San Diego Fire-Rescue spokesman Lee Swanson.

Cinder from a welding operation fell through a grate and ignited debris, which sent up a lot of smoke, Swanson said.

He didn’t know how many people were evacuated when the blaze broke out, but no injuries were reported.

The fire occurred in a bare steel compartment closed to the public and caused minimal damage, said Midway spokesman Scott McGaugh. The museum would open as usual Wednesday, he said.

The attraction along San Diego’s seafront opened in 2004 and hosts as many as a million visitors a year. It has about 200 employees and 650 volunteers.

The Midway, among the largest ships in the world in its early years, was commissioned a week after World War II ended, was used throughout the Vietnam War, and was decommissioned after service in 1991’s Operation Desert Storm.

It now operates as a non-profit run by a board of directors.

In recent years it has been home to college basketball games, used for parties during the Comic-Con pop culture extravaganza, and hosted TV tapings for shows like ABC’s “The Bachelor.”