Tragic F1 track was 'banned' after four deaths and never-before-seen incident which hasn't happened since

A Formula 1 circuit was removed from the calendar by the FIA after four people were killed during its final Grand Prix.

When F1 first began in the 1950s, safety standards were a world away from what fans have become used to seeing in the modern day.

Although there were far fewer Grands Prix, drivers would also race in non-championship and Formula 2 races, with some even occasionally opting to compete in the fearsome Indianapolis 500.

One of the major issues that many tracks had in those days were that the crowd were positioned so close to the action, and with little protection between them and the cars on track.

Guardrails were often the only separation, and even they were not particularly well manufactured or placed at some circuits.

In 1973, Francois Cevert struck a loose guardrail during practice at Watkins Glen and was killed instantly.

His death hastened the retirement of three-time champion Jackie Stewart, who was due to quit at the end of the season but decided not to race in the final Grand Prix.

A similar problem befell the Montjuic Park circuit in Barcelona, which held four Grands Prix between 1969 and 1975.

It was formerly used in non-championship races before the Second World War, but was nowhere to be seen on the calendar when the first F1 Drivers' Championship was held in 1950.

Spanning nearly four kilometres, Montjuic was a high-speed, narrow street circuit which featured significant changes in altitude.

Trees surrounded the track but the only protection for drivers were makeshift guardrails, in an indication of just how dangerous the sport was in those times.

The circuit hosted the Spanish Grand Prix, and alternated with the Jarama circuit positioned north of Madrid.

The first three Grands Prix in Montjuic passed largely without incident, with Jackie Stewart winning in 1969 and 1971 and Emerson Fittipaldi in 1973.

But tragedy struck in 1975.

Hill driver Rolf Stommelen, who had qualified in ninth place out of 26 drivers, suffered a rear wing failure while leading the race on lap 25.

The German's car subsequently launched through one of the barriers and into the crowd, killing two journalists, a fireman and another spectator.

Stommelen himself survived but was badly injured, and missed the next seven Grands Prix before returning in Austria.

The race carried on for a further four laps before being stopped at under half distance, with half points being awarded.

The Grand Prix had otherwise been beset with accidents and mechanical failures, while championship leader Fittipaldi refused to race over safety concerns.

Only eight cars were running at the time of the stoppage, with sixth-placed driver Lella Lombardi becoming the first - and to date, only - woman to score points in Formula 1.

As for the circuit itself, the FIA decided never to return to Montjuic after the disaster.

F1 continued to race at Jarama until 1981, before the Spanish Grand Prix was left off the calendar entirely for the next five years.

Jerez then took over the running of the Grand Prix until 1990, when the purpose-built Circuit de Catalunya - which is still a part of the F1 calendar today - was completed.