A few years ago, engineers sounded alarm bells about Champlain Towers, a residential building in Surfside, Fla. Last week, disaster struck and the towers collapsed. At least 11 residents have been confirmed dead and 150 more are still unaccounted for.What caused the building to fail, and why are so many people still missing?Guest: Patricia Mazzei, the Miami bureau chief for The New York Times. Sign up here to get The Daily in your inbox each morning. And for an exclusive look at how the biggest stories on our show come together, subscribe to our newsletter. Background reading: The collapse of Champlain Towers may be one of the deadliest accidental collapses in American history. Here are the key facts.Some engineers looking at the building’s failure said that the collapse appeared to have begun somewhere near the bottom of the structure.For more information on today’s episode, visit nytimes.com/thedaily.Transcripts of each episode will be made available by the next workday.