Twenty years ago, Queen Elizabeth II and President Francois Mitterrand braved the drizzle to cut the inaugural ribbon of the Channel Tunnel, realising a centuries-old dream of linking France and Britain under the sea.
A prodigious industrial adventure, the project mobilised 12,000 engineers, technicians and workers to create the world's longest underwater tunnel over nearly 38 kilometres (24 miles) from northern France to southern England, earning it the "Global Engineering of the Century Award" by the International Federation of Consulting Engineers.
But this tour de force, officially inaugurated by the Queen and Mitterrand on May 6, 1994, was overshadowed for years by financial problems that almost tore apart Eurotunnel, the company contracted to manage and operate the tunnel until 2086.
At the end of 1987, before work on the tunnel kicked off, hundreds of thousands of eager, small shareholders bought Eurotunnel shares in the belief that these were solid, safe investments.
But colossal debt, disappointing traffic and quarrels between shareholders and management nearly sank the company over the years.
In 1987, shares were worth 35 French francs (the equivalent of 5.34 euros now). Fifteen years later, they were worth just a few centimes each.
The group even saw its stocks suspended for several months as it plunged deeper and deeper into the mire, until a restructuring deal was reached in 2007, paving the way for recovery.
Shareholders finally received their first-ever dividend in 2009, though it was worth just 4 centimes per share.
In 2013, Eurotunnel -- which employs some 3,700 people -- made a net profit of 101 million euros ($140 million), prompting chief executive Jacques Gounon to say: "For the first time in the history of Eurotunnel, we think that the situation of the group is altogether satisfactory."
The idea to end Britain's isolation as an island and dig a tunnel to France emerged as early as the 18th century.
A first project was launched in the 1970s, but was soon abandoned.
Then in January 1986, Mitterrand and British leader Margaret Thatcher officially signed an agreement to kick-start construction.
Thatcher faced considerable opposition to the project within her Conservative Party, but she pushed it through and famously insisted that "not a public penny" would be used.
As such, the contract to conceive, make and put into service the tunnel was awarded to a consortium of ten British and French construction companies grouped under the name TransManche Link.
Construction lasted six years, cost some 15 billion euros and saw workers dig three tunnels -- one for each direction and one in the middle for service work.
Vehicles can only cross the tunnel on board a rail shuttle, "as it is very difficult to ventilate a tunnel... Over a length of 50 kilometres, it's nearly impossible," said Michel Levy of the Setec engineering group, who worked on the project.
The huge, 1,000-tonne tunnel boring machines that dug through the ground got off to a slow start on the French side due to difficult terrain and were slowed down by water infiltrations on the British side.
But finally, in a historical moment, a British and French worker shook hands in December 1990 in the service tunnel, some 100 metres (109 yards) under the Channel.
The tunnel opened in 1994 and, six months later, the first Eurostar passenger train raced through.
After initial disappointing traffic, the number of people using the tunnel increasingly grew and some 330 million passengers have made the trip since 1994.
The tunnel, which carries passengers and freight traffic in separate services, has now become a formidable competitor to maritime ferry services and airlines on the Paris to London route.