This was by far the most interesting day I've ever had with reference to volunteering (DFW Ambassador program) at DFW International Airport. First off, sometime between 7 and 9 AM, an American Airlines Fokker F-100 jet had a nose gear collapse sometime after landing on 17C (center), which in turn required quite a few flights originally scheduled to land on 17C to be rerouted to the west side of the airport and land on 18R. I spoke to a couple of AA pilots, one of which stated he had been rerouted to the Bowie Center and then eventually to Fort Worth Center in order to land on the west side, and another pilot spoke of observing what he described as "12 fire trucks surrounding the F100" and requiring him to land on an alternate runway. Eventually the runway was cleared and the backup of aircraft was reduced. At sometime around 10 AM, one of the cars on the airport train detected some type of debris on the rail system, which resulted in the entire system being shut down for about 90 minutes. Basically since I was working in Terminal A, Station 1 rail station, I had to redirect a lot of employees and flyers to a airport bus that would take them to either their respective terminal or employees parking area. It always seems that the employees are more grouchy about a train being down, than the flying public. Just to show how it affected me; last week I only assisted about 67 people, but today my numbers went up to 102, which was primarily due to the 90 minute train stoppage. As one "75" pilot told me (reference the F100 nose gear failure), "it'll probably be on the news tonight." I hope everyone had a great weekend? Regards, Richard Whitenight