Review of "Deepwater Horizon: A Systems Analysis of the Macondo Disaster"Over the Edge, Brian Hayes. American Scientist, May-June 2017. Review of: Deepwater Horizon: A Systems Analysis of the Macondo Disaster. Earl Boebert and James M. Blossom. 290 pp. Harvard University Press, 2016. Most accounts of the Deepwater Horizon disaster dwell on the drama of the rig’s last hours, as the crew struggled to cope with the well blowout and then fought to survive. Those events are also part of Boebert and Blossom’s story, but the scope of their narrative is broader. Much of the action takes place deep underground, where drilling technology meets the uncertainties of geology, or else miles away in BP’s Houston offices. Their approach is analytic rather than dramatic. Theirs is the account for readers who want to understand how such disasters come about and what strategies might have the best chance of preventing more of them.