A deadly crash in Waterloo on Wednesday morning was partially caused by the stoplights being covered by snow, according to the accident report. The Waterloo Cedar Falls Courier says that 72 year old Dennis Adamson of Dunkerton was traveling south on Airport Boulevard when he allegedly ran a red light and was struck by a vehicle driven by 59 year old Denis Child of Cedar Falls. Adamson told police that his wife, 71 year old Dorothy Adamson, had told him to slow down referencing the snow covered stoplights. Dorothy Adamson was killed in the crash. Both drivers were taken to the hospital with serious injuries.