Just over two hours earlier, at 7:00, this Union Pacific switch job derailed as it was bringing a cut of cars forward (eastward) to clear a switch at Riverside Avenue, and then it was to shove west again to place the cars on another track in nearby West Colton Yard. Unfortunately, it hit the derail on this track, which prevents trains from accidently crossing the BNSF Railway’s San Bernardino Sub. This caused the two SD40N locomotives (UP 1650, the former UP SD40-2 3425, and UPY 3206, which is ex-UP SD40-2 3285, ex-UP 8045, née-UP 3285) to fall to their right. This may have been a braking issue with the equipment. (Union Pacific's Yuma Sub is on the elevated right-of-way and bridge over the BNSF, and next to this track.)
In an odd coincidence, a similar, but worse, accident occurred at this same location nearly two year earlier, in May 2022! (Colton, California - April 30, 2024). Thanks to Mark Johnson for some of the background info on this.
