Oklahoma City firefighters battled a large commercial fire at NW 63 and Western Tuesday night and into Wednesday.

OKCFD Chief Benny Fulkerson said the structure was a large under-construction apartment complex. The top floors of the Canton apartment complex could be seen burning in Twitter posts.

Portions of the building’s top floors could be seen collapsing onto the ground below and near construction equipment.

The fire was still burning as of 9 a.m. Wednesday morning, and fire crews expected they would be working the fire the rest of the day.

"The problem is, we’re just not able to get inside and commit crews to the interior because it’s structurally unsound," Fulkerson said. "There’s a bunch of the deep-seated fire and hotspots that we just can’t access, so ... it’s just going to be a long drawn-out effort to try to get everything completely extinguished."