Exploding Manhole Cover in Action (Animation)

http://nma.tv | http://www.nma.com.tw In Manhattan alone, more than a few hundred manhole covers are sent up in the air each year. These iron discs can weight up to 300 pounds (136kg) and level as high as 50 feet (15m), injuring passer-by's and damaging buildings and cars. Causes include aged and corroded insulation that lead the underground cables to spark, gas and increase pressure to propel the explosions. Researchers are now looking for ways to predict the happenings and prevent them in advance.