For those that are interested in tower crane safety in Singapore here are some important resources:
For those that need some photos to understand how tower crane works here‘s a nice short website (primarily on hammerhead or saddle jib cranes)
Straits Times interviewed an engineer and they came up with 4 possible causes of toper crane crashes
Item 4 is of course irrelevant to this case as the crane was not carrying any load at the time of the accident.
Here’s a listing of some other tower crane collapses in recent years:
In addition, www.craneoperator.com has tons of photos on crane mishaps.