top of that big pile of debris, and then moving it out of the way. part of that rubble could provide crucial evidence in pdetermining what caused this tragedy. >> you have to look at the design of the building, you have to look at the engineering calculations, you have to look at the quality of the construction, but i think in the end, maintenance is probably going to play a significant role in this. >> reporter: the building had recently begun its 40-year structural recertification process. work had started on its roof. but in recent years, it received some scrutiny. in 2015, a tenant sued the condo association, claiming water damage from cracks in her walls. and a 2020 florida international university study found that in the 1990s, the land beneath the building was sinking at a faster rate than neighboring towns. one author telling it it did flag the report. a lot of questions tonight. david? >> so many unanswered questions. victor oquendo tonight, thank you. more from the scene later, but