Having been an insurance claims adjuster for over 8 years I have seen several roofs that failed from the weight of ice and snow. This time of year the weather can be warm enough for rain. 2'-3' of snow and 1/2" of rain equal bad news for roofs! In addition to the weight issue; ice dams can cause issues with interior water damage. Using a roof rake can easily prevent most ice dams since only the lower 8'-12' feet up from the gutter needs to be clear. Most roof rakes come with extension poles that allow the operator to not have to climb a ladder. Finally, I have never heard of anyone falling through a roof while they were in the process of removing the snow.