"On July 5, Pamela Guillen, 40, reportedly suffered a severe subdural haematoma and brain compression after hitting her head multiple times on the X2’s headrest during the [roller coaster] ride."

"She began vomiting and lost consciousness before being rushed to the hospital... Surgeons removed part of her skull to relieve pressure on her brain. She regained consciousness two weeks after the ride and has since had to relearn how to walk and talk.... Six days later Naomi Greer-Wilkinson suffered a traumatic brain injury after riding the X2. Greer-Wilkinson, a 25-year-old from Los Angeles... remains in a coma, connected to a ventilator and feeding tube.... Christopher Hawley, 22, died in June 2022 after hitting his head multiple times against the back of the seat while riding the X2. After finishing the ride, he fell to the ground and became unconscious. When doctors treating Hawley removed part of his skull, they found his brain was so swollen it was bulging out of an opening they made to relieve the pressure...."

From "Two women suffered brain injuries after rollercoaster rides/The X2 rollercoaster at Six Flags Magic Mountain, California, is marketed for the 'ultimate daredevil'" (London Times).