1982, a British Airways B-747 with 247 passengers and 16 crew members was enroute from Kuala Lumpur, Malasia to Perth, Australia. Because of volcano ash, not only did they loose 2 engines, progressively they lost ALL engines. Eventually, 3 engines were restarted and the plane landed in Jakarta.
Here is a link to a very brief synopsis:
http://www.nw.faa.gov/releases/volash.html