Rescue workers digging feverishly for a fifth day Monday stressed that they could still find survivors in the rubble of a collapsed Florida condo building, a hope family members clung to even though no one has been pulled out alive since the first day the structure fell.

The death toll rose by just four people Sunday, to a total of nine confirmed dead. But more than 150 people are still missing in Surfside.

Families of the missing rode buses to a site nearby from which they could watch teams at work Sunday: firefighters, sniffer dogs and search experts employing radar and sonar devices.

U. S. Rep. Debbie Wasserman Schultz said at a Sunday evening news conference that she had met with some of the rescue workers and was able to “hear the hope that they have.”

“We obviously have some realism that we’re dealing with. But … as long as the experts that we trust are telling me they have hope to find people who might have been able to survive, then we have to make sure that we hold on to that hope,” she said.

Israeli Diaspora Affairs Minister Nachman Shai, head of a humanitarian delegation from Israel that includes several search-and-rescue experts, said the professionals have told him of cases where survivors were found after 100 hours or more.

“So don’t lose hope, that’s what I would say,” he said.

Some families had hoped their visit to the site near the 12-story building would allow them to shout messages to loved ones possibly buried deep inside the pile. As they returned to a nearby hotel, several paused to embrace as they got off the bus. Others walked slowly with arms around each other back to the hotel entrance.

“We are just waiting for answers. That’s what we want,” said Dianne Ohayon, whose parents, Myriam and Arnie Notkin, were in the building. “It’s hard to go through these long days and we haven’t gotten any answers yet.”

The building collapsed just days before a deadline for condo owners to start making steep payments toward more than $9 million in repairs that had been recommended nearly three years earlier, in a report that warned of ”major structural damage.”

Authorities on Sunday identified the additional four people that had been recovered as Leon Oliwkowicz, 80; Christina Beatriz Elvira, 74; Ana Ortiz, 46; and Luis Bermudez, 26. The number of people left unaccounted for was 152, said Miami-Dade Mayor Daniella Levine Cava. The last live person rescued was on Thursday, just hours after the collapse.