CNN probe ties Six Flags X2 to life-threatening brain injuries on two riders

CNN's investigation links two July brain injuries on Six Flags Magic Mountain's X2 roller coaster to life-threatening traumas: Pamela Guillen, 40, recovered after emergency brain surgery but needed rehab, and Naomi Greer-Wilkinson, 25, remains in a coma; the ride has been closed as California OSHA investigates, with doctors saying injuries resulted from traumatic acceleration-deceleration on the ride, which has a history of fatalities and prior settlements with Six Flags.