For specific programming tied to 9/11, the places to go in prime time include the 24-hour news networks, as well as History (which repeats The Man Who Predicted 9/11 and 120 Minutes That Changed America) and National Geographic Channel (which presents George W. Bush: The 9/11 Interview, as well as 9/11: Where Were You? and a 9/11-focused installment of Witness). But there’s a coincidental connection to tonight’s new two-hour Discovery Channel documentary as well. The Presidents’ Gatekeepers, which concludes tomorrow night as interviews 20 former White House chiefs of staff, is the latest film by Gedeon and Jules Gaudet – the brothers who made that remarkable, ground-level, as-it-happened 9/11 film shown by CBS.