A tunnel in North Korea collapsed while conducting a nuclear test at that site. Nearly 200 people have been feared to have lost their lives in the collapse. The tunnel collapsed at Punggye-ri during September several days after North Korea conducted the largest nuclear test on September 3. About 100 workers have been injured when the tunnel first collapsed. A Japanese broadcaster said that nearly 200 people are feared to have been dead during the rescue operation. Previously the experts who have checked the land had said that the underground tests would cause the mountain nearby to collapse and it would also result in the leakage of radiation into the atmosphere.
There were many satellite pictures that were taken the day after the test was conducted. There were many alterations in the surface in the picture of Punggye-ri showing tremors. Due to the nuclear blast there had been an earthquake of magnitude of 6.3 which was followed by another earthquake of magnitude 4.1. The bomb that was tested in North Korea was eight times the size of the bomb that was blasted in Hiroshima during the second world war.