In 50+ years of railfanning, I'd never seen this before!
As Union Pacific intermodal train ILBG4-17 (Long Beach CA to Chicago IL) rolls through Beaumont, just about 200 feet (60 meters) or so behind it is UP local LOB86-17! Neither train was moving very fast, but the local (a pair of SD70Ms and three loaded cars) wasn't leaving a lot of room for error. The local is most likely going to stop soon, as there are industries about a mile ahead for which these cars are destined. (Beaumont, California – April 17, 2025)