The crashes that changed Formula One

CNN  — 

Though it has been a divisive addition to Formula One cars this season, the “halo” proved its worth on Sunday during a spectacular opening-corner crash at the Belgian Grand Prix.

When Fernando Alonso’s car was sent airborne after a shunt from Nico Hülkenberg, the halo on Charles Leclerc’s cockpit deflected the impact of the Spaniard’s McLaren.

The titanium structure, built around the cockpit to protect drivers’ heads, sustained severe damage and left many wondering how bad the outcome could have been had it not been there.

Its addition to the sport, which was not without controversy, is just one of a multitude of changes introduced to F1 over the past decades to make the sport safer.

And some of those changes have come as a result of tragic accidents on the track.

READ: Formula One’s “halo” device proves worth at Belgian Grand Prix

READ: Sebastian Vettel wins Belgian GP after avoiding huge opening corner crash

Ayrton Senna and Roland Ratzenberger, San Marino 1994

Security personnel surround the crashed car of Brazilian Formula One driver Ayrton Senna.

Arguably the most high-profile crash in F1 history, Ayrton Senna’s death at the 1994 San Marino Grand Prix – just a day after Roland Ratzenberger was killed during qualifying – brought about some of the most sweeping changes seen in the sport.

A three-time world champion at the time of his death, Senna is still widely considered one of the greatest F1 drivers in history.

There were reports that the Brazilian was left so shaken by Ratzenberger’s death that he was contemplating whether he would even race in the following day’s grand prix.