"In most of our world, Bret's the hero, but in this situation, Kristi was the hero – she saved his life," says Michaels's guitarist and friend, Pete Evick. And Gibson, 39, who has two daughters with Michaels, Raine, 9, and Jorja, 5, did it by keeping her cool.
"I'm used to being calm, because of the times when his blood sugar has gone low, and if I freak out, he freaks out," says Gibson, who spoke to PEOPLE for this week's cover story.
After a CAT scan at a nearby Scottsdale, Ariz., emergency room revealed the bleeding in his brain, Gibson rode with 47-year-old Michaels in the ambulance to St. Joseph's Hospital in Phoenix. "I said, 'I'm not leaving his side,'" says Gibson. "I held his hand and told him, 'It's going to be okay.' Just from his eyes, you could tell how much pain he was in. I wanted to take away that pain so bad."
But all Michaels – who calls his on-and-off relationship with Gibson over the past 16 years "a positive work in progress" – could think of was his family. "He was just worried about me and the girls – that's all he cared about," says Gibson. "I was like don't worry about us, we'll be fine."
To hear from Michaels about the critical minutes after the hemorrhage, the agonizing moments in the hospital and how this brush with death might just change his rock-of-love life, pick up the new issue of PEOPLE, on newsstands Friday