Not sure whether I was a citizen-who-just-happened-to-be-there or a Secret Service agent, but I think the former. Not sure what city it was supposed to be in, though possibly Chicago or possibly someplace in Michigan. The President was there for some event or another — not sure who was President — and just about to move on from one location to another when some kind of medium-sized STOL or possibly even VTOL aircraft went over, low, laboring and billowing smoke. (Imagine a cross between an Osprey and an ATR42, painted mostly white and dull orange, with a big Airbus logo on the side of the forward fuselage. I think the model number ended in -17, or maybe -15. Might have been C-215. Short, wide fuselage, a bulbous nose vaguely reminiscent of a C-130 Hercules, high wing with turboshaft engines at mid-wing driving huge props. Imagine that Airbus designed an aircraft to match the Osprey's capabilities, but for the civilian market.) It looked to be trying to circle around looking for a place to make an emergency landing, but ended up crashing onto the roof of some old metal-roofed sheds or warehouses maybe an eighth of a mile away. No fire, yet.
I ran like hell to get there, along with a number of other people in the vicinity including several of the Secret Service agents. I was first into the building it had pancaked onto the roof of, and to find a route up to the aircraft, which had come through the roof and was hung up in upper-level catwalks and joists. There was a substantial amount of fuel leaking, and sparks and smoke, but no fire yet, although the engines were still running at idle. As more people appeared in the doorway to the warehouse I heard sirens outside, and yelled down that we needed fire-suppressant foam, fast. As I was trying to look in to see if anyone was inside, someone else who'd come up behind me reached in through the shattered windscreen and cut power to the engines. We got around to the other side of the fuselage, dodging streams of fuel pouring from the wing tanks, to find a side cargo door standing open and the aircraft completely empty, although there were two rows of seats, facing inward not forward. There were carabiners — or something very similar, rings at least — bolted to the floor inside the hatch.
This was the moment we realized we'd been had. I turned to the guy next to me, who was one of the Secret Service agents who'd come to the crash site, and said, "This isn't a crash, it's a combined decoy and insertion." He looked back at me, and said, "The President." Then he got on his radio as we both headed for the ladders back down to ground level, about the time a fire crew got inside and started foaming the engines and the spilled fuel. I caught up again at the floor, where he was saying, "No, they'll expect him to be going to the International Memorial Hall, they'll try to hit him there."
Right about there, I woke up, so I don't know what happened next. It was all very Tom Clancy.