Dolly Martinez's cause of death has been revealed. In case you didn't hear the news, the My 600-Lb Life star passed away over the weekend, leaving her family mourning and heartbroken. She was only 30 years old, and her sister Lindsey Cooper shared on Facebook that she was a "loving spirit". Dolly's mom, Staci Thurman, revealed to TMZ on Monday that her daughter's death came as a shock. She said Dolly was admitted to the hospital on March 29th with "fluid on her heart and lungs": "She was put into a medically induced coma and placed on a ventilator the next day, but never recovered.