This (UARS) bus sized satellite was launched in 1991 and was in operation till 2005. After that it has slowly been spiralling into the Earth's atmosphere, breaking up in the process due to the friction, Director General B G Siddharth said in a press release here.
"Smaller parts of the debris could be burnt up but the larger pieces could survive the crash to the Earth. The chances that, a piece of the debris would hit any particular place or person is minuscule, less than one in a thousand billion. However, the chances that the debris may hit some unspecified location on the Earth are higher being about one in three thousand," Siddharth said.
Such (Space Debris hitting the Earth) an event happened in the early 1970s with the Skylab spacecraft though the event passed off without any damage to people or property, he said.
More recently debris from the space shuttle carrying astronaut Kalpana Chawla and crew members (who perished in the Colombia disaster) also hit some parts of the world, again fortunately without damage. The same would be true for UARS too, he added.