Space weather is not something we talk about very often in this blog, but solar storms that bring charged particles towards the earth can cause significant disruptions in communications. The worst ones, like the Carrington event in 1859 that disrupted telegraph service around the world, can shut down anything that is affected by strong electric fields. In our world today, that is almost anything, including power, cell service, vehicles, and utility controls. Right now we are in a period of high solar activity, which makes big solar storms more likely and thus of more concern than in past years. Here is a story from Popular Mechanics that describes what a strong storm from space could do to train and railroad infrastructure: https://www.popularmechanics.com/space/solar-system/a46120073/how-solar-storms-could-affect-trains/.

Source: NASA