In the predawn hours of October 16, 2006, the home of Benny and Martha Cryer exploded. They had lived in the house, in Wylie, Texas, northeast of Dallas, for fifty-two years, but as frantic neighbors helplessly watched, the elderly couple was burned under flaming debris. Both died.

Five months later the Texas Railroad Commission, which regulates the oil and gas business in the state, filed a report that speculated that utility workers digging near the Cryer house might have loosened an underground compression coupling connecting natural-gas lines, allowing leaking gas to build to dangerous levels. It found the gas company, Atmos Energy, blameless and praised its cooperation.

But in the days after the explosion, WFAA-TV in Dallas began its own detailed investigation. It reached a very different conclusion, as we’ll see.

That WFAA has an investigative unit—one that continues to follow the ramifications of the gas-explosion story in 2010—is something of an anomaly in local television these days. In-depth investigative reporting is under siege on every platform in journalism and particularly in local television, where the majority of Americans still get their daily news. Such reporting is difficult, time-consuming, and expensive, not to mention potential fodder for lawsuits. It is also indispensable to a democratic society, shining a bright light on issues, injustices, and problems that otherwise remain hidden from public view.

Still, it is difficult to measure the return on investment from investigative reporting in dollars or ratings. As audiences and revenues continue to decline in an increasingly fragmented news landscape, even stations committed to quality investigative work must continually ask: Can we still afford it? Here’s how one station makes that calculation.

In a glassy, low-slung building in downtown Dallas, WFAA-TV sits alongside The Dallas Morning News and just a few blocks from the infamous former Texas School Book Depository where, from a sixth floor window, Lee Harvey Oswald fired the shots that killed President John F. Kennedy in 1963. In fact, barely two hours after the assassination, WFAA had the first live interview with Abraham Zapruder, the man who made a home movie of the assault on the presidential motorcade as it passed through Dealey Plaza.

Nearly a half-century later, WFAA-TV, the flagship of Dallas-based Belo Corporation’s twenty local stations, has made a name for itself as a place that believes in investigative journalism and finds a way to support it.

That’s a hard and deliberate decision in an industry that has seen viewership and revenues steadily decline over the last decade, as cable and the Internet have siphoned off audience and advertising. “I know viewership is down,” says Michael Valentine, vice president of news at the station.

“There are many more choices, and it becomes incumbent on us to provide unique and compelling content. The investigative unit is certainly part of that.”

Although its revenue losses are not as steep as some of its competitors, Belo, whose stations generally are market leaders, is hardly immune. It reported that its total revenue in the fourth quarter of 2009 declined 13.8 percent from the same quarter a year earlier, and total company revenues for 2009 were down 19.5 percent against 2008.

After cresting at about $22 billion in 2006, revenue for all local U.S. TV stations, including network affiliates and independents, dropped to $20.6 billion in 2008 and was projected to decline 22 percent more—to $16 billion—in 2009. Still, while it may no longer boast the dizzying 50 percent-plus profit margins it enjoyed until about two decades ago, local television—with news broadcasts driving about 44 percent of its revenues—generally is still profitable. Profit margins range from single digits for struggling stations to between 30 and 40 percent for top performers in large markets. The industry has made hard trims recently to insure it stays profitable, shedding about 1,600 jobs in the last two years, out of roughly 30,000.

When personnel cuts come around, investigative teams often are among the first casualties. Their reporters tend to be some of the newsroom’s most experienced and highly paid, and in some cases the unit is assigned a dedicated producer and photographer. That adds up to the kind of money that many cash-strapped stations well might decide to save or reallocate—no matter how prestigious the unit.

That’s what happened in January 2009 when Roberta Baskin, the last remaining member of the investigative unit at Allbritton Communications’ WJLA-TV in Washington, D.C., was laid off—the day after she won a duPont-Columbia Award for exposing a pediatric dental chain that was ripping off Medicaid and other insurers by doing unnecessary procedures on children. The station said steep personnel cutbacks had left it unable to afford specialty reporting.

Lisa Anderson is a 2009-2010 Encore Fellow at CJR. She was the the New York bureau chief and a national correspondent for the Chicago Tribune until December 2008.