I know of 2 witness deaths from refusing blood transfusions.
The first was Josh Tripptree. He was diagnosed with an aggressive type of leukemia at age 16 in 2004 i think. His parents refused blood treatments for a while but the hospital(valley childrens hospital of madera, ca)was able to get a court order to overide the parents authority and administer blood transfusions since he was under age, but the treatments didn't start early enough and from diagnosis till his death was only about a month in length.
The second death was my friend Melissa postal from Temecula, CA(smith I think was her married name) She was about 25 back in 2005 when she bled out after a massive blood clot was dislodged a couple hours after she gave birth. She refused blood and went in for an emergency hysterectomy but passed away on the operating table. Her death really freaked me out at the time as I was also pregnant at the time with my first kid and due a couple months after her. I've never been so scared in my life. I didn't want to give birth. Lucky for me things went smooth but very tragic for melissa. Her son never got to know her.