<p>Heavy snowfall blanketed parts of Britain on Monday, disrupting airports, train networks and roads, and three young boys died after falling into an ice-covered lake as the country recorded its coldest night of the year so far.</p>.<p>Parts of London's underground network were suspended or faced delays, while motorways were gridlocked due to snow. London's Gatwick and Stansted airports warned flight schedules could be disrupted.</p>.<p>The Met Office issued a yellow weather warning for snow and ice in London and south-east England, with ice and fog warnings in other parts of England and the whole of Northern Ireland.</p>.<p>Temperatures dropped below -15 degrees Celsius (5 degrees Fahrenheit) in northern Scotland, with the Met Office confirming it was the coldest night of the year. Further warnings in Scotland and north-east England for potential disruption caused by weather will start at midnight on Tuesday.</p>.<p>Britain's National Grid issued a notification to prepare two winter contingency coal plants, but later cancelled the standby notices as higher nuclear output and wind speeds reduced the chance of energy shortages.</p>.<p>The snow caused problems for commuters and holidaymakers at the start of a fortnight when rail workers and border officials plan industrial action.</p>.<p>Several train operators advised customers not to travel, while emergency services said it was important people take care in the potentially hazardous conditions.</p>.<p>Three boys died and a fourth - aged six - was in critical condition after they fell into an ice-covered lake in Solihull, central England, on Sunday afternoon, as emergency services continued to search the lake to check if anyone else had fallen in.</p>.<p>"The boy's deaths are a tragedy beyond words," Richard Stanton from the local fire and rescue service told a news conference.</p>.<p>"Yesterday's incident is a stark reminder to us all of the dangers of open water, especially during the winter months." </p>
<p>Heavy snowfall blanketed parts of Britain on Monday, disrupting airports, train networks and roads, and three young boys died after falling into an ice-covered lake as the country recorded its coldest night of the year so far.</p>.<p>Parts of London's underground network were suspended or faced delays, while motorways were gridlocked due to snow. London's Gatwick and Stansted airports warned flight schedules could be disrupted.</p>.<p>The Met Office issued a yellow weather warning for snow and ice in London and south-east England, with ice and fog warnings in other parts of England and the whole of Northern Ireland.</p>.<p>Temperatures dropped below -15 degrees Celsius (5 degrees Fahrenheit) in northern Scotland, with the Met Office confirming it was the coldest night of the year. Further warnings in Scotland and north-east England for potential disruption caused by weather will start at midnight on Tuesday.</p>.<p>Britain's National Grid issued a notification to prepare two winter contingency coal plants, but later cancelled the standby notices as higher nuclear output and wind speeds reduced the chance of energy shortages.</p>.<p>The snow caused problems for commuters and holidaymakers at the start of a fortnight when rail workers and border officials plan industrial action.</p>.<p>Several train operators advised customers not to travel, while emergency services said it was important people take care in the potentially hazardous conditions.</p>.<p>Three boys died and a fourth - aged six - was in critical condition after they fell into an ice-covered lake in Solihull, central England, on Sunday afternoon, as emergency services continued to search the lake to check if anyone else had fallen in.</p>.<p>"The boy's deaths are a tragedy beyond words," Richard Stanton from the local fire and rescue service told a news conference.</p>.<p>"Yesterday's incident is a stark reminder to us all of the dangers of open water, especially during the winter months." </p>