I'm new to road biking and just this weekend I rode my 2000 Cannondale R2000 --- purchased on ebay --- for the first time. Unfortunately the ride didn't go so well.
At some point, I heard a metallic popping sound and my rear wheel started skipping back and forth. I nearly lost control of the bike, but was able to slow to a stop without injury. The wheel is completely destroyed: the rim is warped, the tube is punctured, I'm not sure if the spokes can be salvaged, and the tire might also have to go. See the results here and here.
The most disconcerting part of all of this is that I don't know exactly how this happened. There was a pothole on the road but I don't think I hit it. Is there anything that could cause something like this to happen spontaneously? I did not check the spoke tensions before riding, which now I realize was a mistake. I weigh ~190 pounds; could my weight on a wheel with a few loose spokes cause something like this?