A police officer was treated for hypothermia after trying to punch through ice in an effort to rescue children from a lake in Solihull.Superintendent Richard Harris, of West Midlands Police, told reporters that officers entered the water as part of the rescue attempt, with some going in "waist-deep".Three boys aged 11, 10 and eight years old died after falling into icy water on Babbs Mill Lake on Sunday afternoon.A six-year-old boy also remains in critical condition.