As many as five people are dead and 159 missing after a 12-story condo collapse in Miami.

A rescue effort is underway, and members of the Miami community are coming together in the wake of this horrific accident.

At 1:30 a.m. Thursday morning, survivors of the incident say they were awakened by falling debris, fire alarms, and the ground shaking beneath them. “It was like a big thump,” a woman named Fiorella Terenzi said. She thought initially that it was thunder until the sound of sirens filled the early morning darkness. She knew that something terrible had happened.

Witnesses say that the air was full of dust. By Friday morning there were still 159 people unaccounted for leaving family and friends paralyzed with fear. As many as 35 people have already been rescued from the still-intact part of the building and two were pulled from the rubble and taken to local hospitals for treatment said Ray Jadallah, assistant fire chief for the Miami-Dade Fire and Rescue squad.

The building was built in 1981 and located at 8777 Collins Avenue, in the Champlain Towers South unit. The entire complex consists of 136 units of which 55 collapsed. Authorities are not yet sure of the cause, though residents say that in the hours before the collapse, there had been strange creaking sounds that were out of the ordinary.

The area is primarily South American and Jewish. A lawyer involved in building maintenance said that the building had been scheduled to undergo repairs for damaged concrete and rust. The reason is that a review and recertification process is required on buildings that are 40 years old.

Some speculate that the building had been slowly sinking over time and that may have contributed to the collapse. Surveillance video footage shows the building experiencing a progressive collapse. This occurs when the primary structure fails, causing adjoining structural elements to fail too. There is construction work going on nearby and investigators will have to rule out whether that contributed to the weakening of the foundation and structure.

In most of the previous building collapses going back to 1922, poor building practices were the primary cause. On January 28, 1922, the roof caved in after a particularly large snowfall. On January 25, 1971, a luxury condo in Boston collapsed because of the usage of low-quality concrete. On July 17, 1981, the second and fourth- story walkways inside the Hyatt Regency hotel in Kansas City, Mo., collapsed, killing 114 and injuring 200. That incident remains the deadliest non-deliberate structural failure in U.S. history. There have been others since that, including in 1981, 1987, 1994, 2000, 2013, and 2019, and now this one.