(NBC) – A bus exploded in Stockholm, Sweden Sunday rocking the center of the city.
The natural gas-powered bus went up in flames. Fortunately, there were no passengers on board.
The fire sent a plume of black smoke high into the air.
Stockholm police said the driver survived with severe burns.
No one else was known to have been injured.
Police are investigating the fire as a traffic accident saying there were no signs it was terror-related.
A rescue worker told a Swedish newspaper the bus appeared to have collided with barriers at the entrance to a tunnel, causing a gas tank to explode.
The newspaper said the bus was out-of-service on its way to a depot.
