A state of emergency has been declared in Florida as rescuers search for people trapped under the rubble of a collapsed apartment block that has left at least four people dead - with around 160 still unaccounted for.
US President Joe Biden approved the emergency declaration and ordered federal assistance to supplement state and local response efforts in the town of Surfside outside Miami.
Rescue crews picked through tons of rubble on Thursday looking for survivors after the collapse of part of the oceanfront apartment tower.
Watch: Police warn people near site of collapse about smoky conditions
Search teams detected sounds of banging and other noises but no voices coming from the mounds of debris hours after a large section of the Champlain Towers South condominium crumbled to the ground, authorities said.
Dade Mayor Daniella Levine Cava said the number people missing had risen from an initial 99, and that three more bodies were pulled from the wreckage overnight. Another person was reported to have died on Thursday.
Another 102 individuals whose whereabouts were initially unknown have since been located and “declared safe,” she said.
Scores of rescuers earlier pulled survivors from the rubble and twisted metal.
Mayor Charles Burkett warned during a news conference that the building manager told him the tower was quite full and the death toll was likely to rise.
“The building is literally pancaked,” Burkett said. “That is heartbreaking because it doesn’t mean to me that we are going to be as successful as we wanted to be in finding people alive.”
Sally Heyman, a Miami-Dade County Commissioner, said officials have been unable to make contact with 51 people who "supposedly" live in the building, home to a mix of people including families and part-time "snow birds" who spend the winter months in Florida.
US Talk Show Host Andy Slater Tweeted a video he said showed the moment the building collapsed.
Ten people were treated at the scene and two were brought to the hospital, one of whom died, Mr Burkett said, adding that 15 families walked out of the building on their own.
More than 80 fire and rescue units were on the scene of the partial building collapse, the Miami-Dade county Fire Rescue Department said in a tweet early Thursday.
An image posted on Miami Beach Police's Twitter account showed a tangle of rubble with debris spilling down from what was left of the balconies of the building in the darkness.
Teams of fire fighters walked through the rubble, picking up survivors and carrying them from the wreckage.
The collapse left a number of flats in the still-standing part of the building exposed. Television footage showed bunk beds, tables and chairs still left inside the damaged apartments. Air conditioner units were hanging from some parts of the building, where wires now dangled.
Police blocked nearby roads, and scores of fire and rescue vehicles, ambulances and police cars swarmed the area.
The debris from the collapse coated cars up to two blocks away with a light layer of dust.
Eyewitness video obtained by Reuters showed neighbours gathering across the street from the rubble of a collapsed tower.
“This whole building here, it’s completely gone,” a person can be heard saying.
“MBPD and @MiamiBeachFire are assisting the Town of Surfside at a partial building collapse located at 8777 Collins Avenue in Surfside, Florida. Multiple police and fire agencies from across Miami-Dade are assisting,” the police said.
The sea-view condominium development was built in 1981 in the southeast corner of Surfside, on the beach. It had a few two-bedroom units currently on the market, with asking prices of about 700,000 US dollars (£500,000).
The area is a mix of new and old apartments, houses, condominiums and hotels, with restaurants and stores serving an international combination of residents and tourists. The community provides a stark contrast from bustle and glitz of South Beach with a slower paced neighbourhood feel.