The down-at-the-heels industrial city of East Chicago, Indiana, made headlines around the world in August after the mayor ordered 1,000 people to get out of a 40-year-old public-housing complex because of lead contamination.

Many residents and observers expressed surprise: How could such a problem go overlooked for so many decades?

The Chicago bureau’s Sara Burnett and Jason Keyser teamed up for several weeks of intensive document and street reporting. What they found was as disturbing as the original news: The hazard shouldn't have been a surprise to anyone -- because the housing complex had been built on the former site of a lead-products factory.

The hazard shouldn't have been a surprise to anyone -- because the housing complex had been built on the former site of a lead-products factory

Their review of public documents and news coverage dating back to the 1960s showed that officials at half a dozen local, state and federal agencies were aware residents were living on and playing in lead-tainted soil.

Burnett had been tipped off to the East Chicago problem weeks earlier while working another story, enabling Keyser to get the story on the national radar with a piece that chronicled the evacuation order and the response of residents.

Burnett and Keyser then dug deeper. They built an exhaustive timeline, going through reams of digital and library documents and news clips that enabled them to clearly document the decades of neglect that had allowed the residents _ including 700 children _ to be exposed, and how no one could honestly claim to have been surprised.

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This Sept. 14, 2016 photo shows factories in East Chicago, Ind. The mayor of this industrial town ordered the evacuation of a 40-year-old public housing complex this summer because of severe lead contamination, forcing more than 1,000 people from their homes.

AP Photo / Tae-Gyun Kim

What they found and documented was a community that had grown overly accustomed to environmental threats, a string of corrupt leaders and a painfully slow moving health and environmental bureaucracy _ a story that especially resonated in the aftermath of the Flint, Michigan, lead-contaminated water crisis.

Burnett and Keyser’s eye-opening beat came in a week when Chicago colleague Don Babwin had a major beat of his own, breaking the news that the Chicago Police Department would hire more than 500 new officers to combat the city’s violence problem.

Both the East Chicago and Chicago police story were ones covered closely by local and national media. Through thoughtful and focused reporting, Burnett, Keyser and Babwin provided the world with news no one else had.

For thorough and resourceful reporting that shed a unique light on a major story, Burnett and Keyser share win this week’s $300 Best of the States prize.