An attempted robbery at a fast-food joint in Tucson, Ariz., was foiled when bystanders rushed in to thwart the attack.

The Tucson Police Department said that a 34-year-old suspect who has not yet been identified followed a 70-year-old man into a Carl’s Jr. and attempted to steal a backpack from his walker, knocking him down in the process. Two bystanders rushed over and fended off the attacker, then helped the old man up and gathered his scattered items.

The witnesses provided a description of the suspect, leading to his arrest.

Police credited their quick actions with preventing the theft and helping police track down and arrest the would-be thief. The old man suffered a minor injury to his arm and was treated at the scene.