Pope Franciswrote a personal note to a Paralympics star who's fighting for his life after a horrific crash ... saying in the letter, "I am close to you and I pray for you and your family."
The 83-year-old penned the comments to Alex Zanardi -- an ex-Formula 1-racer-turned-amazing-Paralympian who tragically crashed his handbike into a truck in Italy last week.
The scene was terrifying ... Zanardi -- who had both his legs amputated after a racing accident in 2001 -- reportedly suffered massive head trauma in the wreck.
According to officials at the hospital Zanardi is recovering at ... the 53-year-old is in stable condition -- but is in danger of suffering from possible brain damage.
The hospital adds he's been intubated and is on a ventilator.
Enter the Pope ... who after hearing about the accident -- reached out with an emotional letter encouraging Zanardi's recovery.
"Dearest Alessandro, your story is an example of how to start again after an unforeseen stop," the Pope wrote. "Through sport, you have taught us to live life as a protagonist, teaching a lesson of humanity through disability."
"Thank you for having given strength to those who have lost it. In this painful moment, I am close to you and I pray for you and your family."
The Pope signed the letter, "Fraternally, Francis."
Zanardi -- a four-time gold medalist in the Paralympics who's backed the Pope for years with multiple charity donations -- is expected to remain in a medically-induced coma for at least another week.