The Deepwater Horizon oil disaster of 2010 and its continuing impact on the residents of the Gulf—as well as the workers directly affected by it—are the subjects of Margaret Brown’s sober, often moving documentary. But “The Great Invisible” also goes beyond that singular calamity, raising broader questions about America’s lack of a coherent energy policy and the government’s inability to effectively regulate an industry on which it has become so financially dependent.

The terrible explosion that consumed BP’s offshore rig, killing eleven workers, and the monumental discharge of oil into the Gulf of Mexico that resulted from it are depicted brilliantly through the use of found footage and the mournful testimony of two men who lived through it—chief mechanic Doug Brown and roustabout Stephen Stone. Brown in particular grieves over the fact that he was aware of unsafe procedures that were being mandated to cut costs and increase company profits, but both point to an industry culture of manliness that invites a reckless attitude. The traumatic effect of the experience on the two is palpably conveyed, not only in their injuries but in their suicidal impulses. Their observations are buttressed by those of Keith Jones, a lawyer whose son Gordon died in the conflagration and has devoted himself to documenting company practices that contributed to it. Contrast is provided in footage of oilmen talking at conferences about their business, complaining over drinks about governmental regulations that can stifle their freedom of operation, and sequences showing the continuing sale of offshore drilling rights through auctions that bring in huge profits for the treasury—amounts that are second only to taxes as a source of federal revenue.

But “The Great Invisible” is equally about the suffering of locals whose livelihood was threatened, and in some cases destroyed, by the disaster. Brown introduces us to many of them in direct interviews, but also in sequences that follow Roosevelt Harris, a church volunteer who delivers boxes of groceries to families in need and cooks free meals for the hundreds who will come to the church hall for them, as well as Latham Smith, a tugboat captain who speaks from firsthand experience of the loss of jobs that persists in the area, as well as the continuing effect of the spill on marine life (fishermen and shrimpers are still suffering). Her film also points an accusing finger at Kenneth Feinberg, who was appointed to oversee the trust designed to distribute the $20 billion settlement funds to those impacted by the spill—which has proven extremely inefficient—and at Congress, which in the four intervening years has issued not a single new safety regulation covering offshore drilling.

The American people’s attention span is very short as the nation lurches from one crisis to the next. The aftermath of the Deepwater Horizon tragedy is a continuing problem, but one that’s fallen from the public—and political—consciousness. “The Great Invisible” performs a service by reminding us of it, and it does so very well.