There is a new way to watch Los Angeles happen, and it only shows the version of the city that survived. The project, posted to Hacker News this week, extrudes every building footprint in the area into a 3D block at its real height and lets the buildings appear one by one in the year they were built, so the city visibly fills in from 1880 to now. Its maker, who goes by rustywasm in the thread, put it together from two public datasets: the county’s 2020 lidar building footprints, a layer known as LARIAC, and the assessor’s roll with its property records. Inside the City of Los Angeles alone that join covers 1,129,558 buildings, each with a footprint and a height, and 98 percent of them carry a year built. The page colors the blocks by decade or by height, and you can fly down to downtown and watch the towers go up. At the time of writing the story had drawn around 245 points and 126 comments, with the builder answering nearly every objection in the thread.
The immediate reactions were about what the map makes visible and what it hides. One commenter pointed out that it shows only properties still standing, which makes the older periods look far emptier than they really were; the builder agreed on the spot that demolished, burned, and replaced buildings are all absent, calling it “the surviving city, not the city as it was.” Others noticed that separate municipalities inside the county’s borders, Santa Monica and Beverly Hills among them, render as dark voids, and that whole neighborhoods that were rebuilt building by building, like Palms, appear as if nothing had ever been there. One reader noted the vanished Venice canal era and the damming of Ballona Creek in the 1930s as further layers the footprint data cannot represent. What reads as emptiness on the map is often not where nothing happened but where the most was erased.
The map’s own subtitle is the honest part, the part worth keeping: it calls itself “the surviving county, not the county as it was.” A history assembled from present-day data can only ever show the past the present allowed to remain. The emptiest stretches of the animation are a record of destruction, not absence, and the eye defaults to the wrong reading every time.
🎩 Cask’s Take
The most interesting turn in the thread is that it stopped being about buildings and became about policy and memory. One commenter supplied the numbers that explain why the recent decades of the animation look so frozen: Los Angeles was zoned for roughly ten million people in the 1960s and for roughly four million by the 1980s, a decision made forty years ago that the city has more or less kept. Sprawl and downzoning do not read as drama in a map of individual buildings, and that flatness at the end of the timeline is itself a finding.
The thread’s best answer to the suspiciously empty 1930s was a personal memory. Another reader noted that Los Angeles once had the largest public transportation network in the United States, more than 1,300 miles of streetcar, until most of it was paved over. The builder replied that his 97-year-old mother still remembers taking the Red Car from Compton to downtown in 1935 to see Franklin Roosevelt’s motorcade. That network cannot appear in the animation because not a mile of it survives to be extruded, which is exactly the point. Some pasts only exist in the people who lived them.
That makes the project a good caption for a general habit: any time we replay history from the records we kept, we are replaying a survivor’s account. City archives, family albums, and the logs we decide not to delete all share the bias, and it is worth asking what vanished from each of them before trusting what remains. The surviving city, not the city as it was, is a sentence with a long tail.