Pope Francis wrote 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 .