Gas leak likely caused van explosion in Helsinki’s Mellunkylä, police say

Helsinki police suspect a gas cylinder valve left slightly open caused an explosion in a parked van in the Mellunkylä district last October, public broadcaster Yle reports.

The blast occurred shortly after midnight on 20 October 2025 near the intersection of Untamalantie and Tuhkanummentie. Investigators believe acetylene gas, which had leaked from a cylinder into the vehicle’s cargo area, ignited and triggered the explosion.

Two people were injured in the incident, which also damaged nearby vehicles and buildings. The van’s rear compartment contained multiple acetylene cylinders at the time. Acetylene is highly flammable and can explode violently when exposed to static electricity, sparks, hot surfaces, or open flames.

Police have identified one individual suspected of endangering others in connection with the explosion. The case will now proceed to prosecutors for consideration of charges.