No one was injured Friday in a construction site fire at Tribune Tower in Streeterville.

The blaze was reported about noon, and was localized to a landing of a construction site in the rear part of the tower at 435 N. Michigan Ave., Chicago Fire Dept. spokesman Larry Merritt said.

Firefighters put out the fire within 20 minutes, Merritt said. No one was injured or transported to a hospital.

It was unclear what caused the fire, Merritt said. The fire department was investigating.

Tribune Tower is being gutted to be remade into condominiums after its owners sold the building in 2016. Developers have pitched building what would be the city’s second tallest tower on the site.