Giant Pit In Russia - October 21, 2008
Disaster: October 19, 2006 from the potassium mine shaft number 1 Uralkalij (Berezniki town, Perm region), after the collapse, there was a fast increase of water inflow into the face registered. The influx from the aquifer increased, which was extremely dangerous - if saturated with water, solid formation of salt could turn into a pulp, that within a large system of cavities formed in the extraction of salt water, would begin to dissolve rocks with possible effects on surface.
In this situation there was nothing to do, and Oct. 28, 2006 the mine was closed. The process of dissolution of potassium salt in the mine got stronger, and after 9 months, on July 28, 2007, a minor pit had appeared.

The pit was growing very fast, and by the summer of 2008 reached a diameter of 1150 feet and a depth of about 330 feet. Then, the process has slowed down.
Click pictures to enlarge
Not only the territory of the mine was hit by the pit, but also the railway Chusovskaya-Solikamsk (old track is clearly visible on the photo). Passenger trains were canceled as early as 2006, for freight trains there was built temporary bypassing (see the bottom of the picture). Now, suburban and long-distance passenger trains depart from the station Berezniki-Sortirovochnaya located south to the city, where passengers are brought to by bus.
Noteworthy that this incident was not the first. In 1986, at mine number 3 a similar case occurred - strong water inflow into the face after the collapse of the rocks. Then there a pit of similar size appeared, just more elongated. But it happened outside the city, and now residents of Berezniki are going to rest to the lake formed.



Oh right. Haha I get it now