Built on a swamp with a busy road going right through it, what’s now Ronald Reagan National Airport was initially lampooned in news articles as ‘a disgrace.’

But even before the National Transportation Safety Board completes its investigation—a neurotically thorough process that will probably take about a year, and thus meshes poorly with the news cycle and the conspiracy-theorist cycle—it is easy to see some of the lines of inquiry that crash detectives will pursue.