A group of children placed large amounts of leaves into the track on 20 October 1955 a. Tram no. 24 up Eidsvolls gate could not handle the leaves, and started sliding backwards without breaking power. The conductor tried to spread sand on the tracks, but that did not help either. The tram behind, no. 19, noticed this just after leaving Vollabakken, but dared not back up due to the traffic. There were large material damages from the impact, but no-one was seriously injured. Since the two trams were to be taken out of traffic soon, both were withdrawn.