Bob Shamrock, adopted father of champion MMA fighters Ken and Frank Shamrock, passed away yesterday (Jan 14) after a long term battle with different health complications due to Diabetes.

Shamrock was 68 years old.

Bob ran a home in Susanville, CA for troubled kids -- which is how a young Ken Shamrock (then Ken Wayne Nance) ended up on his doorstep at age 13 after several run-ins with the law for strong armed robbery among other things.

Shamrock promoted sports in his community and helped Ken find an outlet through football and wrestling. He also settled house disputes with boxing gloves -- which is where "The World's Most Dangerous Man" first demonstrated his ability to excel at combat sports.

From Ken:

"My dad had an unbelievable light with these kids – I’ve never seen anybody able to take a defiant kid into their home, and handle them like my father could – willing to get into a fight with them if he had to because of disrespect and then turn around and hug them and let them know, the minute you give me respect – I’ll give you respect. Everyone that came in contact with my dad – you could tell he made a difference in their life. I’ve never seen anyone have that much success with kids. I’ll miss him and I’m forever thankful."

Bob legally adopted Ken and his younger brother Frank and both men legally changed their surname to Shamrock out of respect for the man who had done so much to help them.