Boston firefighters work to douse hotspots after dousing a blaze on an under-construction hotel in the city's Theater District on April 4, 2019. Photo courtesy of the Boston Fire Department.

A hotel under construction at the corner of Tremont and Stuart streets in the heart of Boston’s Theater District caught fire Thursday.

The exterior cladding of the the 23-story, 125,000-square-foot, 346-room micro hotel caught fire, according to the Boston Fire Department’s Twitter account.

The fire was located in the narrow space between the hotel and the neighboring Wilbur Theatre.

The cause of the fire has not yet been determined, but is being investigated. No injuries were reported and damage is estimated at $250,000.