"It did exactly what it was expected to do; the predictions, at least the past 24 hours' ones, were spot on; and as expected it fell somewhere empty and did no damage," said Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

It landed about 8:15 a.m. Beijing time (8:15 p.m. ET Sunday), China's Manned Space Agency said.

Leroy Chiao, a former US astronaut who flew on four space missions, told CNN he would be "surprised if any major pieces survived the re-entry, as the Tiangong-1 was not that big of a spacecraft as they go, and it did not have a heat shield."

Anything that did make it through the atmosphere "will be at the bottom of the ocean by now," he added.

The Tiangong-1 was last used by astronauts in 2013, when a three-strong team spent 12 days on the vessel conducting experiments.

Female astronaut Wang Yaping delivered a lecture from space lab to students back on Earth. During its lifespan, it successfully docked with three spacecraft.

Chiao said the original plan was to guide the space station down in a controlled manner, "much like the Mir space station was."

"There's a specific location in the ocean known as the spacecraft graveyard where nations try and put down into," he said.

China also plans to put a man on the moon and send a rover to Mars.

While it's not uncommon for debris such as satellites or spent rocket stages to fall to Earth, large vessels capable of supporting human life are rarer.

The first US space station, the 74-ton Skylab, fell to Earth in an uncontrolled reentry in 1979. Some debris fell in sparsely populated western Australia, causing no problems except for a $400 fine for littering.