Families of the missing visited the scene of the Florida condo building collapse yesterday as rescuers kept digging through the mound of rubble and clinging to hope that someone could yet be alive somewhere under the broken concrete and twisted metal.

The death toll rose by just four people, to a total of nine confirmed dead. But after almost four full days of search-and-rescue efforts, more than 150 additional people were still missing in Surfside. No one has been pulled alive from the pile since Thursday, hours after the collapse.

Some families had hoped their visit would allow them to shout messages to loved ones possibly buried deep inside the pile.

Buses brought several groups of relatives to a place where they could view the pile and the rescuers at work. As relatives 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.

Israeli Diaspora Affairs Minister Nachman Shai, who visited with family members, led a humanitarian delegation to Surfside that included several Israeli experts in search-and-rescue operations. He said the experts 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. But you have everyone understanding the longer it takes, the prospects of finding someone alive goes down,” he said.

Rescuers sought to reassure families that they were doing as much as possible to find missing loved ones, but the crews said they needed to work carefully for the best chance of uncovering survivors.

Crews were also using a microwave radar device developed by NASA’s Jet Propulsion Lab and the Department of Homeland Security that “sees” through up to 8 inches of solid concrete, according to Adrian Garulay, CEO of Spec Ops Group, which sells them. The suitcase-sized device can detect human respiration and heartbeats and was being deployed yesterday.

Miami-Dade Mayor Daniella Levine Cava said six to eight teams are actively searching the pile at any given time, with hundreds of team members on standby ready to rotate in. She said teams have worked around the clock since Thursday, and there was no lack of personnel.

Teams are also working with engineers and sonar to make sure the rescuers are safe.

Crews spent Saturday night digging a trench that stretches 125 feet long, 20 feet across and 40 feet deep which allowed them to find more bodies and human remains.

Authorities are gathering DNA samples from family members to aid in identification. Late Saturday, four of the victims were identified as 54-year-old Stacie Dawn Fang, 83-year-old Antonio Lozano, 79-year-old Gladys Lozano and 54-year-old Manuel LaFont.