You're walking in the middle of the woods along a river. It's nice, and peaceful. It looks perfect. Nothing could ever ruin this for you. Except for maybe an energy blast the equivalent of 30 megatons of TNT leveling everything for hundreds of miles.
Luckily, no one was injured when The Tunguska Event occurred in remote Russia on 30 June 1908.The witnesses saw a blueish light in the sky, followed by a bright flash and the sound of "artillery fire", which produced a shockwave strong enough to knock people over and shatter windows. One eyewitness would later go on to say, "When the sky opened up, hot wind raced between the houses, like from
cannons, which left traces in the ground like pathways, and it damaged
some crops. Later we saw that many windows were shattered, and in the
barn a part of the iron lock snapped."
Because of the isolation of the area, little interest was sparked by this unusual event at the time. The first recorded attempt to investigate it was many years later, in 1921.
The cause of the event is believed to have been an exploding comet or asteroid as it entered Earth's atmosphere. In the '70s a couple physicists believed that it may have been caused by a small black hole passing through Earth, although this theory is considered by many to be flawed. A Science Fiction writer in the '40s wrote a story titled "The Explosion" which blamed the event on aliens.
Below is a map indicating the effected area
Below are a couple photos of the damage