A giant drilling machine punched its way through a final section of Alpine rock on Friday to complete the world's longest tunnel, after 15 years of sometimes lethal construction work.
In a stage-managed breakthrough, attended by some 200 dignitaries 30 kilometres inside the tunnel and broadcast live on Swiss television, engineers from both sides shook hands after the bore had pummeled through the final 1.5 metres of rock.
"Here, in the heart of the Swiss Alps, one of the biggest environmental projects on the continent has become reality," said Swiss Transport Minister Moritz Leuenberger.
"By drilling this tunnel, we are participating in the construction of European infrastructure," he said.
Tunnel workers paid tribute to their colleagues who had died on the construction site with a minute's silence as the names of the eight victims were read out during an emotional ceremony for the breakthrough.
"Workers, thank you, thank you, thank you. We have not only built a tunnel, we have written history," said Luzi Gruber, of the construction company Implenia.
The 57 kilometre (35.4 mile) high-speed rail link, which will open in 2017, will form the lynchpin of a new rail network between northern and southeastern Europe and help ease congestion and pollution in the Swiss Alps.
It is the third tunnel to be built through the snowbound St. Gotthard area but it is much the longest and three kilometres longer than a rail link between two Japanese islands, the current record holder at 53.8-kilometres.
"The myth of the Gotthard has been broken for a third time. Our forefathers struggled from the Middle Ages onwards to make this mountain passable," Peter Fueglistaler, director of the Federal Transport office, told journalists gathered for the final breakthrough.
The breakthrough was also watched by a European Union transport ministers at a meeting in Luxembourg.
Passengers will ultimately be able to speed from the Italian city of Milan to Zurich in less than three hours and further north into Germany, cutting the journey time by an hour.
But the 9.8 billion Swiss franc (7.0 billion euro) tunnel, which is 9.5 metres in diameter, is also the fruit of strong popular wave of environmental concern about pollution in the Swiss Alps with booming road traffic transiting from neighbouring countries.
Switzerland nonetheless struggled to convince sceptical European neighbours to support the ambitious and costly transalpine rail plans.
But they gained added weight in a shock 1994 referendum result when Swiss voters supported an ecologist motion to stop heavy trucks driving across the Alps - including the expanding flow of transiting EU goods traffic.
A nationwide poll published on Wednesday suggested that sentiment is undimmed.
Sixty-seven percent of those surveyed support a ban on truck traffic through the Gotthard road tunnel and move it onto rail, according to the poll commissioned by an Alpine environmental lobby group.
In recent years, Austria, France and Italy have set in motion two similar rail tunnel projects through the eastern and western Alps, that are both planned to exceed 50 kilometres in length in the 2020s.
Once completed, around 300 trains should be able to speed through the Gotthard's twin tubes every day, at up to 250 kilometres per hour (155 mph) for passenger trains.
Apart from the tunnel's economic and environmental implications, the spotlight is on more than 2,000 tunnel workers, especially following the rescue of Chile's trapped miners.
The builders from around a dozen countries, who have blasted and bored through 13 million cubic metres of rock, were feted at a celebration just above the breakthrough point in the mist-bound village of Sedrun.
"The miners are the heroes of today's celebrations," said Renzo Simoni, chief executive of the Alptransit tunnel company.