SURFSIDE, Florida—The slow work of sifting through the remnants of a collapsed Florida condo building stretched into a sixth day Tuesday, as families desperate for progress endured a wrenching wait for answers. “We have people waiting and waiting and waiting for news,” Miami-Dade Mayor Daniella Levine Cava told reporters. “We have them coping with the news that they might not have their loved ones come out alive and still hope against hope that they will. They’re learning that some of their loved ones will come out as body parts. This is the kind of information that is just excruciating for everyone.” The work has been deliberate and treacherous. Thunderstorms rolled through the area Tuesday morning, and debris fell onto the search area overnight from the shattered edge of the part of the building that still stands, forcing rescuers to mark a “don’t go beyond here” line and focus their efforts …