According to the data available from the event recorder, the driver was seemingly prepared to enter the switch leading to track 1 at 80 km/h (50 mph).

[9] The locomotive was thrown some 50 metres (160 ft) away from the track, crossing a highway and hitting a concrete bridge support at approximately 90 km/h (56 mph).

[14][1] Lifting equipment was needed, as many passengers were trapped under overturned carriages; three people were saved from under the cars with air cushions.

The causes became clearer after a few days when the black box of the train was deciphered and the surviving engineer had recovered enough to be heard.

[16] It contained a number signal as a complement to the expect 35 or proceed 35 aspects to allow higher speeds, such as 80 or 110 km/h (50 or 68 mph).

[18] According to the data recovered from the train and subsequent braking tests,[19] it seems that the driver had misinterpreted the signals and arrived at Jyväskylä, fully expecting to enter track 1 at a speed of 80 km/h (50 mph), and, realising what had happened, applied emergency braking just before the fateful switch.

[23] The fireman driving the train was tired as he had finished his previous shift at 06:05 in the morning and had not slept well at the provided facilities at Tampere.

At Jyväskylä, the system would have first warned the driver, then braked automatically 1.4 kilometres (0.87 mi) before the switch, slowing the train to a safe speed.

[31][32] VR implemented airplane-style seatbelts[33] in three InterCity carriages during the year 1999,[34] but finally decided against a wide-range deployment due to their impracticality.