If a self-driving car caused an accident or death, who's at fault?

What are the legal consequences if an accident or death is caused as a result of mechanical failure on a driverless car?

Driverless Cars .. let me pose a Devil's Advocate question

Heres a Devil's Advocate question. With the increase in the 'no hands' parking assistance vehicles now available and (next year) driver-less cars being allowed on Uk roads, how does the driving law equate...