§ 205-d. Relief from civil liability for acts or omissions by fire wardens in the city of New York. After being trained by a certified fire safety director, any person designated to serve as a fire warden or deputy fire warden in any structure classified as an office building by law or otherwise in the city of New York shall not be liable for damages for injuries, death or property damage alleged to have occurred by reason of an act or omission in the performance of any duty contained in a fire safety plan unless it is established that such injuries, death or property damage was caused by gross negligence on the part of such fire warden or deputy fire warden.