Investigators are trying to determine what caused a three-alarm fire that destroyed a newly built apartment apartment building downtown Friday night.

Indianapolis Fire Capt. Rita Burris said investigators remained on the scene Saturday and had not determined the cause or the origin of the blaze that caused $3.5 million in damage and sent black smoke wafting into the sky.

The fire destroyed a four-story, 60-apartment building under construction in the 16 Park development by the Indianapolis Housing Agency. The building was due to open this fall.

16 Park, which was expected to cost a total of $34 million, is replacing the former Caravelle Commons housing development north of East 16th Street between Central and College avenues.

Lt. Larry Tracy says one firefighter was injured and was treated for a possible broken wrist.

Caravelle Commons was a 65-unit, low-income-housing property built in 1975. The seven-acre property had become a magnet for crime, with dead-end streets and fenced-in apartment homes surrounding crowded parking lots. But the Indianapolis Housing Agency was betting the new project would  jump-start more interest in the area.

“We really think this is a transformational development that’s really going to change that part of the neighborhood and that part of the city,” said Bruce Baird, IHA’s director of strategic planning and development, told IBJ last year.

IHA bought the complex in March 2009 from the Near North Development Corp., which took over the Caravelle not-for-profit complex in 2003. Near North stepped in to refinance, renovate and stabilize the property with an eye toward eventually selling it to a more appropriate owner.