Zanardi has surgery after handbike crash.

ROME (AP) — Alex Zanardi, the Italian race car champion who transitioned into a gold medalist Paralympian after losing both of his legs, was seriously injured in a handbike race on Friday.

Zanardi was transported by helicopter to Santa Maria alle Scotte hospital in Siena following a crash near the Tuscan town of Pienza during a national race for Paralympic athletes, police told The Associated Press.

A medical bulletin from the hospital said Zanardi underwent “a delicate neurosurgery operation” due to “severe cranial trauma."

The surgery lasted about three hours, after which Zanardi was moved to the intensive care unit.

“His condition remains very serious,” the hospital said.

Italian Premier Giuseppe Conte tweeted: “You've never given up and with your extraordinary strength within you've overcome a thousand troubles. Forza Alex Zanardi. Don't give up. All of Italy is with you.”

A Carabinieri police official in Montepulciano said the incident involved a “heavy vehicle."

Local TV at the scene of the crash showed what was apparently Zanardi's handbike lying on its side and missing two of its three wheels. A large truck pulling a semitrailer appeared parked on the road ahead.

“It happened on a slightly downhill straightaway just before a slight curve in the road,” national team coach Mario Valentini, who was following the race, told La Repubblica Florence. “Alex veered slightly into the oncoming lane just when a truck came. (The truck) tried to swerve but couldn't avoid the crash."

Prosecutors in Siena opened a criminal investigation into the incident and into the race's organization.

Repubblica said Zanardi remained conscious until medical personnel arrived, and he was breathing by himself.

“Twenty minutes passed from the time of the accident to when the medical personnel arrived. It took some time to load him (into the ambulance). His wife helped. After the accident he was talking,”

Valentini added in another with local media.

Valentini said he was not an eyewitness to the accident but arrived at the scene immediately afterward.

“It was a sunny day and everyone was happy. We were 20 kilometers (12 miles) from (the finish line) in Montalcino," Valentini said. "The truck didn't make a mistake. Alex made the mistake.”

The coach added that Zanardi's helmet came off during the crash.

Racing great Mario Andretti tweeted, “I am so anxious and frightened about Alex Zanardi that I'm holding my breath. I am his fan. I am his friend. Please do what I'm doing and pray pray (for) this wonderful man.”

The 53-year-old Zanardi won two championships in CART In the United States before a brief move to Formula One. He returned to America and was racing in Germany in a CART event in 2001 when both of his legs were severed in a horrific accident the weekend after the Sept. 11 terrorist attacks. interview