ROME (AP) — The mayor of Venice ordered an immediate stop to electric buses operated by La Linea company after a bus crashed in the Italian city, injuring 15 people. This is the company’s second accident following the fiery Oct.3 collision that killed 21 people.

The bus crashed Saturday evening into a building in Mestre, a Venice borough. The injured were not in serious condition, Mayor Luigi Brugnaro said in a statement.

On Oct. 3, an all-electric bus — carrying foreign tourists — fell from an elevated street in Mestre en route to a camping site near the community of Marghera. The bus fell a few meters before crashing close to railway tracks, where it caught fire.

The Italian driver and 20 foreign tourists were killed.

City officials suggested the driver, Alberto Rizzotto, who had an untarnished record, may have suffered a heart attack. But according to the local daily Corriere del Veneto, preliminary results of his autopsy dispelled that.

The investigation is still ongoing.