Was it intentional? Was this the start of a robot uprising that went bad? We may never know. On a more serious note, while we get scared by these things, sometimes issues happen. The Great Chicago Fire (of 1871) cost much more than that, killed some 300 people, and was rumored to have been started by a cow tipping over a lantern.
Safety is a massive unaddressed issue in the rapidly evolving automation sector.
Found at www.zdnet.com