Why did a US gunship destroy a hospital?

On October 3, 2015, an American gunship destroyed a Doctors Without Borders hospital in Afghanistan, killing 42 people. The US government's report ruled that it was an accident. But did Afghan forces, out of a longstanding mistrust for the NGO and its policy of treating all sides, mislead the US military into a devastating tragedy? In this weekend's issue of the New York Times Magazine, I investigate: