Helicopters used for security drill in Chicago

July 21, 2009 (CHICAGO) It was only a security drill in preparation for President Obama's visit to Chicago later in the week.

According to officials with the Secret Service, the helicopters are manned by Marines who are working on logistics.

ABC7 Chicago viewer Mark Troup sent in a photo of the helicopters.

President Obama will be in Chicago Thursday to attend a private dinner. He also will meet with some members of the Chicago Bulls to help raise money for Democrats.