INDIANAPOLIS — A large fire gutted a luxury apartment complex under construction a few blocks from the Statehouse early today, with bright flames consuming the six-story building and gray smoke billowing across the downtown skyline.

The building was not yet occupied and no injuries were reported.

The $28 million Cosmopolitan on the Canal complex was considered a total loss, said fire department spokeswoman Rita Reith. The complex was beside a pedestrian walkway-lined canal near several other residential and office buildings.

The cause of the fire, which broke out about 3:30 a.m., was not determined.

About 125 firefighters brought the fire under control, said Reith. A portion of the building collapsed and firefighters were still working on the smoldering structure some five hours later.

Mayor Greg Ballard said firefighters kept the flames from spreading to adjacent, occupied buildings.

Mark Conover, a spokesman for project developer Flaherty & Collins Properties, said the complex consisted of 218 apartments.