The Tiangong-1 space lab was placed in orbit in 2011. Pic/AFP

A defunct Chinese space lab disintegrated under intense heat as it hurtled through Earth's atmosphere Monday and plunged towards a watery grave in the South Pacific, Chinese officials said. The Tiangong-1 "mostly" burnt up above the vast ocean's central region, China's Manned Space Engineering Office said. There was no immediate confirmation of the final resting place of any remaining debris, although the South Pacific is largely empty.