This is really a kudos to my colleague Bill Dedman, whom I worked with on this three-part series. 

Bill writes: 

FBI agents are interviewing employees at FEMA in an investigation of unusual changes in federal flood insurance maps that benefited oceanfront condo buildings with a history of flooding, according to sources familiar with the investigation.

The investigation follows a report by NBC News documenting more than 500 instances in which FEMA has remapped waterfront properties from the highest-risk flood zone, saving the owners as much as 97 percent on the premiums they pay into the financially strained National Flood Insurance Program.

FBI agents have conducted interviews in Washington over the past 10 days with employees of the Federal Emergency Management Agency, which oversees the flood insurance program. Others outside the government also have been interviewed and have voluntarily provided documents, according to two people interviewed by the FBI. Employees at contractors that evaluate the map changes for FEMA are also being interviewed.

Sitting in on the FBI interviews are investigators from the Office of the Inspector General at the U.S. Department of Homeland Security, according to the sources. FEMA, which has said it would review the flood map changes identified by NBC, is an agency within the DHS 

Asked about the FBI investigation, a FEMA official referred all questions to the Office of the Inspector General, whose spokesman said, “As a matter of policy, the Office of Inspector General does not discuss investigative matters.” The FBI also declined to comment.

Read the initial series: Why Taxpayers Will Bail Out the Rich When the Next Storm Hits, Meet the Flood Insurance ‘Robin Hood’ Who Saves Condo Owners Millions, For Average Joes, Fighting FEMA Flood Maps Isn’t Easy or Cheap