Want to know why mail drones aren't ready for prime time? The Siberian town of Ulan-Ude was expecting to beam with pride as organizer Rudron/Expeditor 3M tested a postal drone in the area for the first time, but they left red-faced after the inaugural flight went spectacularly wrong. The hexacopter courier went haywire moments after takeoff, smacking into the side of a building at high speed -- as you can see in the video below, it went from technological triumph to an embarrassing pile of scrap metal in a matter of seconds. It was a costly crash, too, as the drone reportedly cost about $20,000. It's not certain what went wrong, although regional leader Alexei Tsydenov speculated to Reuters that the 100-plus WiFi signals in the area might have played a part.