The US air force has confirmed the reentry of the Tiangong-1 spacecraft at about 02:16 CEST this morning over the southern Pacific Ocean. The location of the reentry was, by chance, not too far from the so-called South Pacific Ocean Unpopulated Area. The SPOUA has long been used by many space agencies including ESA, to dispose of end-of-life spacecraft through controlled reentries. 

The air force wrote:

The JFSCC used the Space Surveillance Network sensors and their orbital analysis system to confirm Tiangong-1’s reentry, and to refine its prediction and ultimately provide more fidelity as the reentry time approached. This information is publicly-available on USSTRATCOM’s website www.Space-Track.org. The JFSCC also confirmed reentry through coordination with counterparts in Australia, Canada, France, Germany, Italy, Japan, South Korea, and the United Kingdom.

JFSCC tracks Tiangong-1’s reentry over the Pacific Ocean

VANDENBERG AIR FORCE BASE, Calif. — U.S. Strategic Command’s (USSTRATCOM) Joint Force Space Component Command (JFSCC), through the Joint Space Operations Center (JSpOC), confirmed Tiangong-1 reentered the Earth’s atmosphere over the southern Pacific Ocean at approximately 5:16 p.m. (PST) April 1, 2018.

There’s also a nice report via Euronews:

China’s old space lab crashes into South Pacific | Euronews

China’s defunct Tiangong-1 space lab has finally crashed into the Pacific Ocean after re-entering Earth’s atmosphere, according to the country’s space agency.

The spacecraft re-turned at 0015 GMT on Monday and mostly burnt up on re-entry. What was left hit the ocean north-west of Tahiti.

Tiangong-1 was launched in 2011 to carry out docking and orbit experiments.

It was part of the country’s efforts to build a manned space station by 2022 but stopped working in March 2016.