Just 12 days after actor Dennis Quaid and his wife, Kimberly, welcomed their twins
, Thomas Boone and Zoe Grace, on Nov. 8, the parents were dealing with devastating news: The babies, after being admitted to Cedars-Sinai
Medical Center in L.A., were accidentally given a dangerous overdose of a blood thinner, PEOPLE recounts in its latest cover story.
"She could barely get out three sentences," Kimberly's brother Blake Buffington says of how his sister broke the news to him. "She said they weren't sure if they were going to make it. She told me, 'The babies are fighting for their lives.' "
For Dennis, 53, and Kimberly, 36, it has been one medical nightmare after another. Within a week of being brought home to the Quaids' house in L.A., the twins were hospitalized at Cedars-Sinai due to staph infections. At the hospital on Nov. 18, they were allegedly among three patients given 1,000 times the recommended dose of heparin, a drug used to prevent IV catheters from clotting. The dosage was high enough to cause severe bleeding and death if left untreated.
"The babies are still at the hospital in intensive care," Buffington said on Nov. 27. "We're hoping they get to come home from the hospital, but we don't know how long that will be. Kimberly has gotten to hold them a few times, but they are on monitors and IVs, so it's hard. You have these fragile little kids going through a medical crisis they absolutely did not need to go through."
For more on this story, including what long-term effects may exist and how the Quaids are coping, pick up this week's PEOPLE, on newsstands Friday