Five people have now been confirmed dead after one more body was pulled from the rubble of a collapsed apartment complex in Miami, Florida.
Speaking at a news conference, Miami-Dade county mayor Daniella Levine Cava also said search and rescue teams had discovered other unspecified human remains.
A huge section of the 12-storey Champlain Towers South building in Surfside was reduced to rubble when it crashed to the ground around 1.30am on Thursday local time (6.30am UK time).
The number of people now unaccounted for has dropped to 156, while those accounted for stands at 130.
Ms Levine Cava said the ongoing rescue operation was being severely hampered by a fire within the wreckage, but added: “Our top priority continues to be search and rescue and saving any lives that we can.”
Officials said they still held hope that some of those unaccounted for might be found alive.
Aided by dogs, infrared scanning and heavy equipment, rescuers hope that air pockets that may have formed in the debris might keep people alive.
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“The biggest thing now is hope,” Miami-Dade fire chief Alan Cominsky said. “That’s what’s driving us. It’s an extremely difficult situation.”
Earlier on Saturday, Ms Levine Cava said, a blaze “very deep” in the debris had posed “incredible difficulties” to the rescue teams because of the flames.
At one point, a fire hose blasted one of the lower floors on the north side of the tower as white smoke or steam streamed out, and a bitter, sulfur-like smell hung in the air.
Among those anxiously waiting for news of missing loved ones is Rachel Spiegel, whose mother, 66-year-old Judy Spiegel, lived on the sixth floor.
Speaking alongside her siblings, she said “we’re trying to hold it together”.
“I know my mom is a fighter. I know she loves us. I know she doesn’t want to give up. So, you know, it’s day three, so it’s hard,” Ms Spiegel added.
President Joe Biden said he had spoken with Florida Governor Ron DeSantis to offer assistance as needed.
“My heart is with the community of Surfside as they grieve their lost loved ones and wait anxiously as search and rescue efforts continue,” Mr Biden tweeted.
Meanwhile, a newly released 2018 report showed that an engineer found evidence of major structural damage beneath the pool deck and “concrete deterioration” in the underground parking garage of Champlain Towers South, three years before it collapsed without warning on Thursday.
Authorities said they will start an audit within the next 30 days of nearby buildings approaching their 40-year review to ensure their safety.