I think we are forgetting that we do train in budo, a martial way. These techniques can be fatal when applied correctly. Death can happen at any instant. Bad ukemi, failure to get out of the way of a bokken strike, pushing ourselves too hard, negligence and malice is not required for injury. The gods do as they will.
Aikido is oftentime preached as being the martial art that everyone can perform. I think this encourages a lot of people who probably should not train in budo to join an aikido dojo. Budo is hardwork; it is a method for spiritual warriors to forge their body, mind and spirt. It is not for everyone.
There are various paths a person can follow to The Way (e.g. yoga, shodo), but budo is the only path where we learn to kill as we undertake our spiritual journey. Death on the mat is a real possibility. Everytime I walk onto the mat I acknowledge that, as should everyone and pray that my uke and I walkaway unharmed. By living under the blade we learn that life is truly delicate and precious. Every moment is a gift from the Divine.
May the God and Goddess have mercy on those who died along the path, but it is better to die along the path then to have never walked it at all.