The grim, painstaking search for victims in the rubble of a partially collapsed Miami-area condominium complex, briefly suspended over safety concerns, has resumed with greater caution and a watchful eye on a tropical storm headed toward Florida.

The confirmed death toll stood at 18, with 145 other people still missing and feared buried beneath tons of pulverized concrete, twisted metal and splintered lumber as the search stretched into its ninth day early on Friday.

Two of the dead were children, aged 4 and 10.

Authorities had halted the rescue-and-recovery effort early Thursday for fear that a section of the high-rise tower still standing might topple onto search crews in the debris field.

But the operation was restarted about 15 hours later when it was deemed safe, though with a new set of precautionary measures in place, Miami-Dade County Fire and Rescue Chief Alan Cominsky told reporters Thursday evening.

Under the new search plan, teams would confine their work for now to just three of nine grids demarcated in the ruins of the 12-floor Champlain Towers South condo, Cominsky said.

Authorities were eager to make as much progress as possible before expected arrival of Tropical Storm Elsa, which was blowing in from Atlantic.

The storm was on track to begin lashing South Florida with high winds and heavy rain by late Sunday, according to the National Hurricane Center in Miami.

The renewed search effort began shortly after a visit to the scene by U.S. President Joe Biden, who spent about three hours consoling families of the dead and missing in the oceanfront town of Surfside, adjacent to Miami Beach.

The president also met with first-responders, and was briefed by state and local leaders, including Governor Ron DeSantis, widely seen as a potential Republican White House candidate in 2024.

Biden, a Democrat, told them he would deliver “whatever you need” in federal assistance, including temporary housing for survivors.

Biden, whose personal experience with tragedy has helped define his political persona, acknowledged that prospects for finding more survivors dimmed with each passing day, but said it was possible someone might still be found alive.

“Hope springs eternal,” he said at a news conference at the nearby St. Regis hotel after meeting privately with affected families and before viewing flowers and posters woven into a fence as an impromptu memorial near the ruins.

“The whole nation is mourning with these families. They see it every day on television, they’re going through hell,” he told reporters. “I sat with one woman who lost her husband and her little baby boy and didn’t know what to do.”

Nobody has been rescued from the fallen building since the hours immediately after about half of the 136-unit building caved in on itself in the middle of the night, as residents slept.

Investigators have not determined what caused nearly half of the 40-year-old condo complex to crumble into a heap in one of the deadliest building collapses in U.S. history.

But a 2018 engineering report prepared ahead of a building safety-recertification process found structural deficiencies in the condo complex that are now the focus of various inquiries, including a grand jury examination.

As recently as April of this year, the condo association president warned residents in a letter that severe concrete damage identified by the engineer around the base of the building had grown “significantly worse.”