Norway's hopes of a medal in the men's lightweight double skulls were dashed after their boat capsized.
Kristoffer Brun and Are Weierholt Strandli were in second place when their boat toppled over with just 500 metres to go in the semi finals.
The pair were keen to upgrade their bronze medal from Rio in 2016 to a silver or a bronze this year, but now they are left to wonder what might have been.
Commentators described the moment as "heartbreaking" and the pair looked on in despair as their opponents rowed off towards the finish line.
They held onto their boat until lifeguards came to help them.
Once they were back upright, Brun and Strandli crossed the finish line in a time of 12:16:25 - double the time it took the Germans, who went on to win the race.
They will now compete in tomorrow's B final.
Britain failed to win a gold medal for the first time in the coxless four race since 1996 after they veered out of their lane and nearly hit the Italian team.
The crew were well within reach of a medal as they entered the final 500m of the race before a steering malfunction caused them to zig-zag back and forth across their lane, considerably slowing their progress and indeed that of the Italian crew in the adjacent lane.
Errors in steering are hugely uncommon at this level of the sport, and there was disbelief amongst the rowing community at this untimely failure.
Double Olympic gold medallist James Cracknell was unsurprisingly blunt in his judgement: “Someone in the British crew blew up. The only way your steering goes like that is when somebody totally runs out of juice.”
In a shocking turn of events, Team GB rower Matt Rossiter accused previous British winners in the men's four as feeling "smug" after a hectic finish saw his crew miss out on a medal.
The 31-year-old suggested that previous Team GB winners of the event would be pleased about the current crop's failure:
He fumed: "It’s just disappointing that those people will be really smug now that they are part of the legacy that won.
"That was a motivation to do well. I hope those people are happy we have not continued the gold run.”
Britain did achieve success in the men's quadruple sculls as Harry Leask, Angus Groom, Tom Barras and Jack Beaumont claimed silver in a tight race at Tokyo 2020.
The group managed to fend off Poland and Australia to finish second, which is the team GB’s first medal in rowing at these Games.
