TWO AMAZING women, Barbara Laker and Wendy Ruderman, just won the Pulitzer for their work for the

Daily News

- and for our city.

They investigated narcotics cops who lied about evidence. Their series, "Tainted Justice," bubbles like the best potboiler - until you remember that real people were brought down by this corrupt team of police.

According to the Daily News' victory-lap article in the paper on the day after the prize was announced, the investigation changed police policy, prompted an FBI investigation and gave a chance for freedom to more than 50 people who may have been wrongfully convicted based on the work of these officers.

It's clear that justice - for each family that had a loved one torn away, for a city that needs its police force to fight crime, not cause it - is priceless, but the investigative journalism that leads to justice has a price tag. In this economy, it makes sense to ask how much that reporting costs.

ProPublica and the New York Times collaborated on an article that shared the Pulitzer with our reporters at the Daily News. Dr. Sheri Fink's piece on the choices health-care workers made in a hospital crippled by Hurricane Katrina made for a gripping read in the New York Times Magazine. The story laid a foundation for the choices made in humanitarian and crisis situations, a template that we can bring into many future crises. It also cost $400,000, according to Times editor Gerald Marzorati.

Our winner at the Daily News cost considerably less, according to Gar Joseph, the city editor who shepherded the investigation for a year. His "back-of-the-envelope" estimate, not including overhead, and printing and delivery costs, was $164,000.

The question isn't whether this kind of journalism has to cost that much. In poorer cities like Philadelphia, investigative journalism can save communities, businesses, even lives.

And the question isn't whether we can rely on blogs and independent journalism to fill the gap. As incredible blogging and independent media projects are growing and building capacity, we still must turn to papers like the DN to invest the skills and resources needed to undertake big-bang investigations like this one.

The question is how do we sustain investigative journalism in Philadelphia - because we and our neighbors certainly can't live without it.

In 2008, Mayor Nutter tried to close 11 libraries in Philly neighborhoods. The economic crisis had gutted our budget, and he wanted to balance the books by cutting essential services. The mayor claimed that there was a library within two miles of every resident in the city - and said we should take our medicine.

The Coalition to Save the Libraries formed lightning fast, and ran effective press stunts and more substantive events across the city to fight the closures. But we wouldn't have saved those libraries without the investigative reporting by Isaiah Thompson of the City Paper.

His reporting showed that if the mayor got his way and was able to close 11 libraries, there wouldn't be a library within two miles for every Philadelphian.

What are those libraries worth to the thousands of Philadelphia families who depend on them to apply for jobs, study, have a safe place to go to after school? And is the justice in the DN series worth more than $164,000?

In 2007, friends of mine were evicted from their home after they and their neighbors asked questions about newly omnipresent surveillance cameras on their block. When the cops showed up at their front door, arrested them, kept them in jail for 14 hours and somehow got the L&I department to condemn the home, it was the reporting of Dave Davies and his colleagues at the Daily News that demonstrated that the cops were trying to pin charges on the homeowners without just cause, and asked readers to consider that the police actions might be tied to the political stands the homeowners took.

If these are the abuses that journalism uncovers for us in our city, what level of corruption might we expect if we no longer have reporters digging for them?

WE NEED more investigation, not less, in Philly. The Daily News and its sister paper, the Inquirer, are under threat of being sold to investors who may no longer have an interest in the quality of journalism produced - and our city can't afford to lose a huge linchpin in the network of reporting that holds the powers that be accountable.

As the consequences of the economic crisis continue to hit us and our neighbors, our daily struggles and the injustices we face will become invisible - unless we have help in the fight to tell our stories.

Hannah Jane Sassaman is a longtime Philadelphian who works with the Media Mobilizing Project.