Whilst we don't know the full facts (and in cases like this we often never do) it would seem that Benoit killed his wife and child before committing suicide.
As for the reasons why, well, it can be for a whole myriad of reasons. Though his career with the WWE is unlikely to be the main cause it could well be a contributing factor (these guys spend a lot of time on the road) in the sense that there were marriage difficulties or other pressures arising from it, this though is mere speculation at this moment in time and doesn't really add anything to the current state of affairs. However, I'm sure that over the coming weeks information will show up and people will begin to piece together what actually went wrong.
In response to Griffo - this won't have any real effect on the WWE and even if there were to be some factor implicating the industry what can be done.
People accept that if you want to wrestle you have to put the hard yards in. Sometimes the actions that people take to get there aren't always ethical but the alleged steroid abuse is no different from that of many other sports, much the same as the lack of what could be considered a normal family life.
As to the industry being controversial, well, I fail to see it that way. The only really controversial aspect of the sport is that it is based around storylines, which do mean that outcomes are know beforehand and that they occasionally step over the boundary of good taste. All wrestling fans know and accept this for what it is - sports entertainment.
It's only the idiots looking in from the outside who feel to play on the 'it's fake' angle mainly because they fail to understand and are worried that they are missing out on the joke. Just because it's scripted to some extent does it make it any less entertaining or mean that the risks are in any way diminished?