As of Monday, we were aware of the Miami building collapse investigation

(CNN) – City officials say the cause of the area building collapse in Miami is not yet known, but engineering reports, investigations and residents have shed light on the integrity of the structure as rescue workers continue to find survivors.

At least 10 people were killed, 151 were missing and 135 were missing in the southern fall of Champlain Towers Sunday night, Miami-Tate County Mayor Daniel Levine Cava told a news conference.

Here is what we learned about the research so far:

The 2018 report generates an alarm: The 2018 report, completed by Morabido Consultancy, a structural engineering firm, “describes significant cracks and fractures in concrete,” the company said in a statement on Saturday. The committee said it gave the building association an estimate for making “comprehensive and necessary repairs.” The report did not specify whether the structure was in danger of collapsing. The report said that in June 2020 Morabido was again hired by the Building Association for repair and renovation work.

At the time of the collapse, roof repair work was underway, but concrete restoration had not begun, he said, adding that the company “exclusively” provides engineering consulting services and did not provide construction-related services.

“We are deeply concerned about the collapse of this building and are working closely with investigators to understand why the system failed. As we do so, we continue to pray for all those affected by this tragic incident,” the company said in a statement.

One researcher says that condo showed signs of sinking in the 1990s: Shimon Vodovinsky, a professor at the Florida International University Institute for the Environment, told CNN in a study last year that the Sampline Towers South Condo showed signs of sinking in the 1990s. The condo had a rate of two millimeters between 1993 and 1999, according to their study. Although Wdowinski said this fall would not only cause a condo collapse, he said it could be a contributing factor. “If one part of the building moves relative to another, it can cause some tension and cracks,” he explains.

Residents raised concerns about the quake while constructing a nearby building: Eleana Salshawer, one of Florida’s three city commissioners, told CNN Sunday night that survivors of the crash said they had spoken of a nearby building in recent years. Salshaur, some of the survivors, told him he was upset that their building had been shaken. They told him there were tremors, cracks and water leaks in the garage, he said.

Local leaders are now reviewing construction protocols: The catastrophic collapse prompted nearby towns and cities to reconsider their building renovation protocols. 5 miles from Surface, the Sunny Islands coastal city will begin sending teams to inspect the buildings after it was announced Saturday that it will reverse the current process of building restoration for 40 years, Deputy Mayor Larissa Schwess told CNN.

On Friday, the city of Miami sent out a letter asking Miami’s communications director Stephanie Severino to ask CNN to get an inspection from a qualified structural engineer with more than six stories and buildings over 40 years old. They are asked to respond within 45 days with any structural concern.

Boca Raton Mayor Scott Singer told CNN in an email on Sunday that his city was developing “strict standards for building certification” following a landslide.