Spaniard Alonso of Ferrari was left as a stranded victim of a multiple collision triggered by Frenchman Grosjean’s impetuous aggression.
Alonso said: “I’m disappointed because of the points lost, but I’m also lucky that I can be in the car in five days at Monza because — looking at the images — we were turning in so you could have a problem with your hands or even your head because Grosjean’s car was so close.
“I think we broke everything on top of the car. It was lucky in that aspect.”
Alonso said he could not understand how the accident happened until he saw the replays.
He said: “I didn’t know what happened until I saw it on TV because it was difficult to imagine how the hit could be so big or how a car could be on you so quickly.
“After seeing it on TV, I saw Grosjean and Lewis touch each other. They lost control and then it was in front of us.”
The Spaniard took a few moments to assess his condition before climbing from his wrecked Ferrari.
“I stayed in the car for a few seconds because I had back pain,” he explained.
“Then there was a little bit of fire so they came with extinguishers and I decided to jump out because I could not breathe with all the smoke there.”
Alonso added that the start had been eventful even before the accident.
“The first thing was (Pastor) Maldonado,” he said. “I was surprised because we still had the red lights and he was already P3 or P2.
“So it was a big jumped start. Then the start was good, I overtook the two Saubers and was in third position. Then I started turning in and then it felt like a train coming. It was a big, big hit.”
Alonso’s elimination meant the end of his unbroken run of points-scoring finishes this year – and saw his lead in the title race cut to 24 points.