CHAPTER ONE began on Aug. 29, 2005, when New Orleans’s levees broke. The Louisiana Superdome swelled with survivors, rescue boats navigated the fetid roads turned into canals, and desperate, crying people dominated the evening news. Katrina destroyed more than 850,000 homes. The hurricane wreaked the most harm in the poorest neighborhoods of New Orleans, destroying 80 percent of the city’s affordable-housing units. Katrina was our nation’s homegrown debacle.

Chapter 2 was the hopeful renaissance, with a special focus on the private sector. Thirteen months post-disaster, the once-crammed-with-Katrina-survivors stadium hosted the NFL’s Monday Night Football game. The refurbished stadium — with a $180 million facelift — presaged recovery. National organizations, starting with the American Library Association, returned to New Orleans for national conferences. French Quarter restaurants served beignets and gumbo.

Chapter 3 — a lengthy, optimistic section — featured the legions of volunteers. Instead of spending spring break in Daytona, college students built homes, repaired roofs, worked in legal-aid clinics. Under the aegis of Habitat for Humanity, more than 70,000 volunteers worked throughout the Gulf Coast. Hundreds of thousands more gave money. (The Habitat affiliate in New Orleans accounted for 12 percent of all single-family new construction in New Orleans in 2006.) Other nonprofits, including the Red Cross, NeighborWorks and Enterprise Community Partners, flocked to help. So did religious groups from across the nation. All the volunteers and their organizers deserve bows.

But even after the surge of philanthropy, New Orleans remains not so much a work-in-progress, as a work that has not progressed very much. Houses, apartments, storefronts and churches stand empty and unrepaired. New construction waits for sewer lines, water and electricity.

Chapter 4 has focused on blame. In a variation of the child’s game “pass the button,” analysts have tossed the blame from the Army Corps of Engineers (for not dredging deep enough and fast enough) to municipal red tape (for almost everything), to the Federal Emergency Management Agency (for everything), to insurance companies (for using the Jesuitical distinction between wind and water damage to deny compensation), to corruption (for misspending), to speculators (for buying up abandoned property), to property laws (for making it hard to demolish dilapidated structures), even to the people left stranded, who are blamed for not coming back, or for coming back to dilapidated housing. Graduate students will be writing dissertations on Katrina’s aftermath for decades.

At this point, much of the national media (with some notable exceptions) have abandoned the story, in part, I suspect, because the story is so depressing: Two years post-Katrina, people still live in temporary shelters. Admittedly, the volunteers have helped many people. One Habitat volunteer and Katrina survivor from Bay St. Louis, Miss., said: “If it wasn’t for God and the faith-based groups like Habitat, there’d be nothing down here still. Absolutely nothing.” But the volunteers in and of themselves cannot resurrect the city of New Orleans.

It is time for the next chapter. Call it Government Leads.

The private sector — philanthropic and corporate — has made inroads, but it has not sufficed. This chapter will turn to the people we elect at all levels of government. Federal, state, and local government must look beyond their jurisdictional turfs. The tasks at hand are mundane yet crucial: sewers, sanitation, water, safe levees, trash removal, local land use plans, public transportation, schools that teach, and public safety that protects people in every neighborhood.

This chapter can feature a truly rebuilt New Orleans: no more temporary shelters, no more rubble, no more streets without electricity. The city will once again fill with families — both families who want to return, and new families, drawn to a great place to live.

Nicolas P. Retsinas, of Providence, is chairman of Habitat for Humanity International.