UPDATE as of 4:40 pm: Black Hills Energy has the gas leak under control. The evacuation order is lifted; people are now permitted to re-enter the area and return to their homes.

Original story follows:

Msg from Seward County KS Emergency Management: DUE TO A LARGE GAS LEAK, THE 700 AND 800 BLOCKS OF SOUTH CAIN AND SOUTH CALHOUN WILL BE EVACUATED AND UNINHABITABLE FOR UP TO TWO HOURS