SURFSIDE, Fla. (AP) — With nearly 160 people unaccounted for and at least four dead after a seaside condominium tower collapsed into a smoldering heap of twisted metal and concrete, rescuers used both heavy equipment and their own hands to comb through the wreckage on Friday in an increasingly desperate search for survivors.

As scores of firefighters in Surfside, just north of Miami, toiled to locate and reach anyone still alive in the remains of the 12-story Champlain Towers South, hopes rested on how quickly crews using dogs and microphones could complete their grim, yet delicate task.

"Any...