The Miami condo tower collapse that has killed at least nine people and left 152 more unaccounted for appears to have been caused by a failure at the bottom of the 13-story building. A team of structural engineers studying footage of the disaster that sent more than 50 apartment residences crashing to the ground has pinpointed a possible failure near the ground floor. “It does appear to start either at or very near the bottom of the structure,” Donald Dusenberry, a consulting engineer who specializes in structural collapses, told The New York Times. “It’s not like there’s a failure high and it pancaked down.” Three years ago, a structural engineer hired by the Champlain Towers South identified “major structural damage” to the building’s concrete foundations and “abundant” cracks in the parking garage. Residents have said that they had felt the building shaking in recent years while construction was going on nearby.