Driving home from work on the interstate during heavy rain when all of a sudden the passenger window started to make grinding/crackling noises - and out of nowhere without any moment of rolling up or down the window, POP! The window fell down while it was pouring out on I-275, my passenger was shook and all wet after we arrived at a nearby gas station to tape up the passenger window since it couldn't go up anymore. This has never happened before and there was no indication/signs of a failing window regulator before it completely dropped the window.