A two-alarm fire caused some damage before it was contained Wednesday night at the main Grain Exchange building in downtown Minneapolis. No one was hurt.

The blaze originated on first floor of 400 S. 4th St., one of three Grain Exchange buildings, about 6:30 p.m., according to the Fire Department. Flames were quickly knocked down, but smoke was thick inside the building afterward.

The 138-year-old building was evacuated as firefighters searched several floors. They broke windows to ventilate the structure and used water to wash down the area.

Police cordoned off the entire block, and many emergency vehicles came to the scene.

Madison Hershkovitz, of Minneapolis, was among several people at a potluck dinner for students and their families at Prime Digital Academy, whose offices are adjacent to where the fire broke out. An instructor at the accelerated software engineering school smelled smoke and ended the event early.

“I started coughing,” said Hershkovitz, who went on the balcony to grab her backpack. “That’s why it smells like a barbecue.”

The cause of the fire is under investigation. It remains unclear how long the historic building will remain closed.