Button: Halo cockpit wouldn’t have affected Alonso’s situation

Alonso managed to extricate himself from his McLaren, which came to rest on its side after rolling several times.

Button claims that if Alonso's car was fitted with the Halo head protection system, even if it had hampered his escape he wouldn't have suffered any negative consequences.

"He didn't need to get out [quickly] in that situation," said Button. "There's more safety risk of things hitting our head than anything happening when the car's upside down.

"It's very unusual they'd be an issue with fuel spillage, because of the safety cell and the tank.

"It just won't happen, so it's better to have a Halo system. [Marshals] would tip the car over, of course, to get him out. It would take a bit longer, but he was OK, so it doesn't matter."

"Amazed" Alonso walked away

Button said he was shocked by the severity of Alonso's crash, caused when he clashed wheels with the Haas of Esteban Gutierrez.

"I didn't see the incident, I saw the red flag and the team said both drivers are OK,' Button added. "I thought 'strange to have a red flag' and then I saw Fernando walking away, and then I saw the incident, and I'm amazed that he did walk away.

"It just proves how far we've come with the cars in terms of safety – as it proved, there's still a lot of possible danger, especially in a braking zone, it's always the worst. The closing speed, if one car is braking and the other one isn't, it's massive.

"It look like that's what happened, a slight misjudgement by one of the drivers, tyres touch and then it's just a bullet when the suspension is not on the car any more."

Alonso relieved to be alive

Alonso put the collision down to a racing accident.

He said after the shunt: "Scary moment and a scary crash. Lucky to be here. It's thanks to the FIA, and all of the safety, probably thanks to that I am alive.

"We lost probably the whole car and the power unit, a lot of damage, but I'm super happy to be here."

Speaking about the moments that led to the shunt, Gutierrez added: "I had straight-line braking on the normal point, obviously I was aware that he was behind and... everything was a surprise, it came very quickly."