Following the collapse of the Twin Towers, air quality became an issue of prime concern for the residents of lower Manhattan. However, the Environmental Protection Agency, at the urging of the White House, deleted cautionary statements and added reassuring ones in early press reports about the air quality in lower Manhattan. By declaring the air outside Ground Zero as "safe," based on inadequate data and analysis and in the face of New Yorkers' own experiences of difficult breathing, the EPA undermined its own credibility, not only on this sensitive issue, but perhaps on future ones as well.
Reference
Office of Inspector General. EPA's response to the World Trade Center collapse: Challenges, successes, and areas for improvement. Report No. 2003-P-00012. Washington, DC: U.S. Department of Environmental Protection; August 21, 2003.