Armchair Japan fans following their team's 2-1 World Cup win over Colombia risked triggering a plumbing disaster of biblical proportions when millions rushed to the toilet at half-time. It was a case of squeaky bum time when fans finally tore themselves away from the television earlier this week after a nail-biting first 45 minutes, with water use jumping 24 percent in Tokyo during the break, the city's waterworks bureau said on Friday. "We presume it's because a lot of people holding off on a trip to the bathroom all went at once," an official told AFP. "Water use can fluctuate, especially during football matches, which only have one break in the middle," she added. "It also can be affected by a period of time, excitement and other factors." Flushed with joy after watching Yuya Osako bag a second-half winner for Japan against 10-man Colombia in Russia on Tuesday, jubilant fans made another dash for the loo at the final whistle, causing another spike of 50 percent in water use.