At least four people are dead and 159 are unaccounted for after a building partially collapsed in Miami on Thursday (June 24). Friday morning (June 25), Miami-Dade County Mayor Daniella Levine Cava confirmed the number of fatalities and said search and rescue efforts are ongoing.

“Tragically, I woke up to learn that three bodies had been pulled from the rubble last night,” the mayor told ABC’s “Good Morning America.” “Devastating news for families waiting for any hope of survival. And of course, we’re going to continue to search. Those three people have not been identified at this time. It does bring our count to four of those who’ve lost their lives in this tragedy.”

The 12-story Surfside building that partially collapsed was found to be unstable last year, USA Today reports. A professor at Florida International University’s Department of Earth and Environment told the outlet that the high rise has been sinking at an alarming rate since the 90s.

Raide Jadallah, the assistant chief of operations for Miami-Dade Fire Rescue, said 55 of the building’s 136 units collapsed around 1:30 a.m. local time. Officials pulled 35 people out of the rubble on Thursday afternoon and as of Friday morning, 129 people have been rescued.

“It is a very slow and methodical process because every time we start breaching parts of the structure, we get debris that falls on us,” Jadallah told NBC News. “We did receive sounds, not necessarily people talking, but sounds… of a possibility of a banging… Short of that, we haven’t heard any voices coming from the pile.”

According to NBC, a police investigation into the collapse is currently underway. Gov. Ron DeSantis also declared a state of emergency in the county and President Biden approved an emergency declaration, which allows the Department of Homeland Security and Federal Emergency Management Agency “to coordinate all disaster relief efforts.”

See some videos and pictures of rescue efforts from the tragedy on Twitter below.