Yesterday marked the 20th anniversary of the death of Ayrton Senna.

The Brazilian, at the time considered to be among the leading drivers in Formula One, was killed in a crash at the San Marino Grand Prix; his Williams car coming off the racing line on lap seven and colliding with an unprotected concrete barrier. Senna had been travelling at 190 miles per hour.

These are the facts of an incident after which Formula One was left to pick up the pieces, but it made an impact too on the nascent racing career of David Marshall Coulthard. The Scot was known better as another moniker in 1994: simply a test driver for the Williams team.

It was the sort of role considered to be a way in to F1 - it also earned Coulthard enough money to pay his rent - although the narrative was made more compelling given that it was Senna who had also held the door open for him. The three-time world champion had watched as the young Scot tested his car and had been left so impressed that he advised that Williams consider Coulthard as a potential team driver.

The weight of that recommendation could keep Coulthard rooted to the belief that he would become a driver in F1, an ambition which remained unalloyed even after Senna's death. The Scot was asked to serve as Williams' No.2 driver in the Spanish Grand Prix later that year alongside Damon Hill, an offer he heard clearly despite the exhaustive conversation about whether or not the car was safe to race in.

"The thoughts that might have occurred to other people - such as, is it safe to get in this car? - never occurred to me," said Coulthard. "I was a 23-year-old making my way. You don't think about death. The thought process is simple: it doesn't happen to you."

Any doubts might have been drowned out by the whispers of a quiet life back in his hometown of Twynholm had the Scot turned down Williams. It was a career far removed from the revving engines of a Formula One grid, soundtracked instead by the job of keeping things ticking over as part of the family transport business.

"In many ways, I owe my career to Ayrton's death," said Coulthard, who would compete in 247 races and win 13 times before retiring in 2008. "At the time, I was in my third year of F3000 and I had no money. My family had helped me a lot, but the sums were getting too big and they had made it clear I was on my own.

"I was not far away from running out of options and heading back to Scotland to run the family transport business, knowing I'd tried everything. The Williams test drive was really important to me, largely because I was paid. It wasn't a lot in F1 terms - about £30,000, I think - but it meant I could pay my rent in Milton Keynes while I tried to work on my racing options.

"Julian Jakobi, who was involved in Senna's management, told me, in the context of my getting the Williams drive, that Ayrton had been impressed with my testing and suggested I might be a good option for the future.

"I remember at the time thinking that Ayrton was the best driver in the world, it was unlikely I was going to be as good as him and all I could do in his honour was give 100% every time I was in the car."

He took his place on the grid for the first time in Barcelona. It was a moment marked by the nerves associated with a competitive debut, but not the death of a hero. "It was clear it [Senna's crash] had been an absolutely survivable accident on any other day; it was just terribly unfortunate that the suspension arm penetrated Senna's helmet," he said. "Many people having seen pictures of the broken steering column, thought he'd gone straight on because the steering had failed.

"But you can't have load and a broken column at the same time. The sensor is black and white. So everything was there to tell the engineers that they could send the car back out with confidence."

Senna had given his blessing to Coulthard already.