An autonomous food delivery robot caught fire on a Berkeley, California walkway on Friday. The robot is part of a fleet of robots manufactured and managed by the startup, Kiwi. The company released a statement in which it said that an idling robot caught fire, leading to smoke and flames.

A member of the community extinguished the flames using a fire extinguisher, and the fire department arrived shortly to secure the scene.

According to Kiwi, the root cause of the incident was human error when replacing the batteries, where a defective battery was put in place of a functioning one. The company also stated that it has put in custom software that will rigorously monitor the state of each battery.