…on the night of April 24th or the morning of the 25th, Russian cruise missiles destroyed a total of six traction substations within the Ukrainian rail system, paralyzing electric train traffic (and thus, all rail traffic) in western Ukraine.
Traction substations house transformers that take power from the grid and convert it to the voltage, amperage, and frequency needed to drive electric train motors through overhead lines or (more often) third rails.
As you can see from this map, the strikes were clearly intended to paralyze rail traffic throughout roughly the westernmost one-third of the Ukraine.
American Buddhist Net 