Florida Gov. Ron DeSantis warned that residents of the Champlain Towers’ sister building near Miami may need to evacuate out of an abundance of caution as investigators have yet to determine the cause of the South building’s unexpected collapse Thursday morning.

"It was built at the same time with the same designer, so they are looking at working with them, and I know they are considering potentially evacuating them, but that’s something that ultimately the mayor is going to have to make the call on," DeSantis said during a Saturday morning news conference in Surfside, east of Miami.

Florida Gov. Ron DeSantis, second from left, speaks during a news conference near the scene where a wing of a 12-story beachfront condo building collapsed, Thursday, June 24, 2021, in Surfside, Florida. At left is Lt. Gov. Jeanette Nunez. (Associated Press)

Surfside Mayor Charles Burkett is the one who would make that decision. 

He has said that he was concerned about the sister building’s structural integrity but was not "philosophically comfortable" ordering people out, according to the New York Times.

MIAMI HIGH RISE COLLAPSE: AROUND-THE-CLOCK RESCUE EFFORT CONTINUES AS FEDERAL TEAM PREPS FOR INVESTIGATION

"I can’t tell you, I can’t assure you, that the building is safe," he reportedly told town commissioners at a meeting Friday.

The collapse killed at least five people, and 156 remained unaccounted for as of Saturday evening, with search efforts underway but few new signs of life following hopeful evidence picked up on sonar equipment a day earlier.

Investigators have not yet dug into the rubble to determine a cause of the collapse, but experts have floated a few possibilities. Some ideas include structural damage over time that could have weakened the edifice or something undermining the foundation, causing it to give out.

Surfside town public records reveal that an engineering firm determined the building had sustained major structural damage over the years.

The 2018 report, from Morabito Consultants, inspected about half of the building’s 136 units as well as the roof, exterior and other common areas.

Photos of missing residents are posted at a makeshift memorial at the site of a collapsed building in Surfside, Florida, north of Miami Beach, on June 26, 2021. (Getty Images)

Morabito also found cracked tiles on multiple boundaries, which the report said were evidence of structural damage beneath the surface. Inspectors also observed concrete cracking and spalling observed on the building’s exterior.

MIAMI CONDO COLLAPSE: HOW LONG MIGHT VICTIMS SURVIVE IN THE RUBBLE?

"The extensive soffit damage is a systemic issue that can only be repaired by removing all of the balcony tile, repairing the damaged concrete surfaces at the top and bottom of the slab and protecting the slab by installing a pedestrian waterproofing membrane," the report reads.

Waterproofing in the pool area was also observed to be "beyond its useful life and in need of complete replacement."

"The failed waterproofing is causing major structural damage to the concrete structural slab below these areas," the report reads. "Failure to replace the waterproofing in the near future will cause the extent of the concrete deterioration to expand exponentially."

The report described this as a "major error" in the building’s 1981 construction and found the slab under the drive and pool deck was flat – not graded – and prevented proper water drainage.

There was "abundant" cracking and spalls in the concrete columns in the parking garage, beams and walls, according to the report. It also deemed prior spot repairs "poor workmanship."

In addition to the structural issues, the report also found that common maintenance items like new sliding doors and windows had been improperly installed and were leaking. The building was also missing Occupational Safety and Health Administration-required suspension hooks for window washers.

A group of scientists and engineers from the National Institute of Standards and Technology is expected to arrive in Miami and conduct a firsthand review of the collapsed building once the search and rescue operation comes to a close.

CLICK HERE TO GET THE FOX NEWS APP

They will be tasked with collecting preliminary data that will then be used to determine the federal government’s next steps.

"If a full investigation or study is conducted, its ultimate goal would be to determine the technical cause of the collapse and, if indicated, to recommend changes to building codes, standards and practices, or other appropriate actions to improve the structural safety of buildings," said the agency’s acting director of public affairs, Jennifer Huergo.

Whether there is a threat to neighboring buildings or similar high rises up and down the East Coast may not be known until the NIST investigation is complete, Glenn Corbett, a former member of the Federal Advisory Committee of the National Construction Safety Team told Fox News Friday.

"They’re the federal government’s technical capability in terms of doing an investigation, finding out why the building collapsed and coming up with recommendations for the future," he said.