A massive search and rescue operation is underway after a portion of a 12-story condo building in Surfside, Florida, collapsed early Thursday morning, according to AP.

The state of play: Rescuers have pulled at least 35 people from the rubble, and two people have been sent to a hospital, one of whom died. Authorities have not yet established what may have caused the collapse.

BREAKING: Miami-Dade County mayor updates on "unimaginable" building collapse.

- 12-story building with more than 130 units; "about half of those have collapsed."
- Massive search and rescue underway
- Family reunification hotline: 305-614-1819 or https://t.co/yTvJzvjNjmpic.twitter.com/K83w1fW4XD

— ABC News (@ABC) June 24, 2021

What they're saying: Miami-Dade County Mayor Daniella Levine Cava said at a press conference Thursday that a family reunification hotline has been set up after the "unimaginable" collapse.

• "What we know at this point is the Champlain Towers South is a 12-story building, it's more than 130 units and about half of those collapsed," Cava said.