Updated

Rescue and recovery workers who helped in the aftermath of the Sept. 11 terrorist attacks are planning to gather at the 9/11 memorial this month to commemorate the 10-year anniversary of the official end of the cleanup at ground zero.

Mayor Michael Bloomberg announced the May 30 evening event on Tuesday, and warned spots are limited.

Bloomberg is the chairman of the 9/11 memorial. He said in a statement the event will honor the sacrifices made by first responders and recovery workers whose efforts "were nothing short of heroic."

The event gives officials the chance to focus on the workers who toiled in the days after the attacks. Some first responders objected when only the family members of 9/11 victims were allowed to attend anniversary observances on Sept. 11, 2011.