BOSTON -- A man who led a failed effort to bring IndyCar racing to Boston is suing the city.

WGBH-FM reported Thursday that former Boston Grand Prix CEO John Casey has filed a lawsuit in Suffolk Superior Court seeking $15.5 million in damages.

Casey sued city Environment, Energy and Open Space chief Austin Blackmon this year. That lawsuit was dismissed in July because state law doesn't allow public employees to be sued individually for negligence.

Casey argues in both lawsuits Blackmon waited months to inform race organizers about changes to federal flood maps, leading to delays in the permitting process that doomed the race. The Boston IndyCar race was slated for this past Labor Day weekend.

Democratic Mayor Marty Walsh's office has declined to comment.