VIDEO: Evacuation and frozen zones have shrunk as efforts to stabilize an under-construction high-rise in Midtown Manhattan continued on Tuesday night.

The installation of temporary shoring has begun at a high-rise at 235 E. 42nd St. after a structural column buckled on the 21st floor, said Department of Buildings Commissioner Ahmed Tigani in a Tuesday evening update.

“We were able to get to the 21st floor to inspect the work that’s being done and feel confident that the emergency work is stabilizing the situation,” Tigani said, and also referenced a third party engineer that has been brought in for another set of eyes.

Around 8 a.m., construction workers noticed cracks inside the building. The FDNY says the workers spotted structural support columns beginning to buckle on the 21st and 22nd floors and self-evacuated.

Officials say that caused the 21st to 26th floors of the 37-story building to start caving under the stress.

The fear, officials said, is a partial collapse, which could be internal. A full collapse onto the street is less likely, Fire Chief John Esposito said at Tuesday’s news conference.

WABC-TV ABC 7 New York City