In 1908 something, thought to be a carbonaceous chondrite or possibly a small cometary nucleus, entered the Earth's atmosphere and exploded in the air above the evergreen forests of Tunguska, flattening trees over an area of about 20,000 square kilometeres in extent. The trees beneath the epicenter of the blast were stripped, but remained standing, indicating that the exploding object had not reached ground level. [link]
. I've selected this individual link as a sport of summary [link]
. I suspect English was not the author's first language.