72, en route from Iisalmi to Helsinki via Kouvola, was scheduled to pass VR freight train 2051 in Airaksela, 20 kilometres (12 mi) north of Suonenjoki, with the freight train waiting on the passing loop and the InterCity using the main line.

The train dispatcher was planning to make the pass at Suonenjoki railway station, which would delay the departure of the InterCity by three minutes.

A route was secured for the InterCity to Suonenjoki railway station, where it was signaled to stop and wait for the freight train to pass.

[2] However, before the freight train could arrive at Suonenjoki, the InterCity left the station on schedule at 5:57:01, missing the red "stop" aspect of the signal.

This forced the rear end of the locomotive to rise high up in the air and touch the overhead lines.