“We noticed that a lot of people were out on the ice so we issued a warning over the radio,” Christina Johansson from Stockholm police told the Dagens Nyheter (DN) newspaper.
However the warning almost came too late for one couple who fell through the ice near Lilla Essingen in the city centre. The couple managed to climb back up but were brought to hospital suffering from hypothermia.
Anders Wernesten, a spokesperson for the Swedish Life Saving Society said that the ice can be deceptive as the snow covers hidden melted patches. Sluice gates connecting Mälaren to the sea have also been opened recently to lower water levels in the lake, leading to increased currents under the ice.
“With the sun warming the ice from above and warmer current eating into it from underneath, there is a really strong risk of going through the thinner ice,” he told DN.
“All of a sudden you can fall through the crust and end up in a kind of sorbet slush that is very hard to get out of.”
About a quarter of all drowning accidents in Sweden are related to people falling through ice, mainly during spring. Emergency services advise walkers and skiers to avoid going on the ice alone and to bring proper equipment, including ice picks.