These figures show why the building collapsed.  The images are from a Chinese newspaper and from the bbs.sina.com.cn website.  The translations were forwarded to me in an email (Unfortunately, I can’t read Mandarin).

(1) An underground garage was being dug on the south side, to a depth of 4.6 meters
(2) The excavated dirt was being piled up on the north side, to a height of 10 meters
(3) The building experienced uneven lateral pressure from south and north
(4) This resulted in a lateral pressure of 3,000 tones, which was greater than why the pilings could tolerate.  Thus the building toppled over in the southerly direction.

First, the apartment building was constructed

Then the plan called for an underground garage to be dug out.
The excavated soil was piled up on the other side of the building.

Heavy rains resulted in water seeping into the ground.

The building began to shift and the concrete pilings were snapped
due to the uneven lateral pressures.

The building began to tilt.

And thus came the eighth wonder of the world.