SURFSIDE, Fla. (AP) - Florida officials are working on plans to tear down what’s left of a partially collapsed oceanfront condominium building after concerns about the structure’s instability prompted a 15-hour halt to the search for survivors.

After rescue efforts resumed Thursday evening, officials said they had started planning for the likely demolition of the remaining structure even as searchers continue to comb the rubble pile beneath it.

Scott Nacheman, a FEMA structures specialist, said engineers are looking at different methods for the demolition and how to proceed “to make the site safe for ongoing rescue operations.”

Nacheman said that if the building comes down, there initially will be a slowdown in the rescue operation. But he said the demolition of the structure would create a safer working environment that could allow more personnel on the site and accelerate the pace of the work.

He said it would likely be weeks before officials schedule the demolition.

Miami-Dade County Mayor Daniella Levine Cava said the decision about the demolition needs to be made “extremely carefully and methodically,” considering the potential impact on the pile of debris and the effect on the search.

The rescue work was halted early Thursday after crews noticed widening cracks and up to a foot of movement in a large column.

Work resumed shortly before 5 p.m. after the site was evaluated by structural engineers, Cava said, describing firefighters as “really, really excited out there.”

“We will continue to search feverishly, as we have done all along in the parts of the collapse that we currently have access to,” she said.

The work stoppage had threatened to dim hopes for finding anyone alive in the debris a week after the tower came down.

Surfside Mayor Charles Burkett said the halt was worrisome since “minutes and hours matter, lives are at stake.”

The temporary halt to rescue operations unfolded on the same day that President Joe Biden and first lady Jill Biden visited the devastated community.

The collapse of the 12-story Champlain Towers South condominium killed at least 18 people and left 145 missing. No one has been rescued since the first hours after the collapse.