The precarious search operation turned lacerating as the victims this time include the children aged 4 and 10, a loss that Miami-Dade mayor called “too great to bear”.

Mayor Daniella Levine Cava who made the announcement apparently shattered took a deep breath, stared down at her notes and spoke haltingly and said the disclosure came with “great sorrow, real pain”.

Miami-Dade police later identified the children as 10-year-old Lucia Guara and 4-year-old Emma Guara. The remains of their father, Marcus Guara, 52, were pulled from the rubble on Saturday and identified Monday. The girls and their mother, Anaely Rodriguez, 42, were recovered on Wednesday.

Search crews going through the ruins found the remains of a total of six people Wednesday, bringing the number of confirmed dead to 18.

It was the highest one-day toll since the building collapsed last Thursday into a mound of concrete. The number of residents unaccounted for stands at 145.

Earlier in the day, crews searching for survivors built a ramp that should allow the use of heavier equipment, potentially accelerating the removal of concrete that “could lead to incredibly good news events,” the state fire marshal said.

Miami-Dade Assistant Fire Chief Raide Jadallah told family members of those missing that the ramp allowed rescuers to use a crane on sections that were not previously accessible. He said that improves the chances of finding new pockets of space in the urgent search for survivors.

“We hope to start seeing some significant improvement in regards to the possibility of (finding) any voids that we cannot see,” Jadallah said.

The new equipment includes a so-called nibbler, a massive machine that has a scissors-like tool at the end of a long arm to cut through concrete and rebar.

Officials have been concerned an underground parking garage could collapse under the weight of heavy equipment, so they decided to build the makeshift limestone ramp, Patronis said. He said dogs are used to check for survivors in the area where the machine works, and then the nibbler is sent in.

“So you can really make some serious rapid headway just because of the sheer hydraulic forces this thing can exert versus a human being with hand tools,” Patronis said.

The cause of the collapse is under investigation. A 2018 engineering report found that the building’s ground-floor pool deck was resting on a concrete slab that had “major structural damage” and needed extensive repairs. The report also found “abundant cracking” of concrete columns, beams and walls in the parking garage.

Just two months before the building came down, the president of its board wrote a letter to residents saying that structural problems identified in the 2018 inspection had “gotten significantly worse” and that major repairs would cost at least $15.5 million.

Officials were also worried about the possibility of severe weather interfering with search efforts. Crews have already had to deal with intermittent bad weather that caused temporary delays in the work, and they are now keeping an eye on a potential tropical storm in the Atlantic Ocean.

Gov. Ron DeSantis said some of the resources in Surfside might have to be removed in case the storms hit any part of Florida.

The possibility of severe weather prompted state officials to ask the federal government for an additional search and rescue team. Kevin Guthrie of the Florida Division of Emergency Management said the new team would be on hand if severe weather hits, allowing crews that have been working at the site for days to rotate out.

Authorities said it’s still a search-and-rescue operation, but no one has been found alive since hours after the collapse on Thursday.

President Joe Biden and first lady Jill Biden planned to travel to Surfside on Thursday.

Miami-Dade Police Director Freddy Ramirez said he hopes Biden’s visit will be a morale booster for the devastated community.

“We’ve had several challenges from weather, sorrow, pain. And I think that the president coming will bring some unity here for our community, support, like our governor, our mayor, all of us together.”