The Tiangong-1 satellite was launched in 2011, and should have come back down to Earth in the ocean in a controlled crash. But watchers have said that it now appears to have gone into freewill, with China losing control of it, and so it could crash down onto the Earth any time.
The huge size of the satellite mean that parts of it could still make their way through the searing heat of entry back into the atmosphere, and so cause problems when they arrive back on Earth.
http://www.independent.co.uk/life-st...-a7132401.html
US Skylab crashed into Australia. Russian MIR spacestation was dropped to the ocean. And now we have a huge satellite hurtling towards the Earth.
"Take a look to the sky just before you die" (c) Metallica
PS. I know it's some ridiculous 0.000000000001%, but anyway... just want to know your opinion.