(AP) - Officials say at least two more people have died following the vicious winter storm that ravaged the eastern U.S. over the weekend.

A 12-year-old girl was killed in suburban Chicago after a snow fort collapsed while she was playing outside a church as temperatures hovered around 14 degrees (minus-10 Celsius). A utility worker in Connecticut was fatally struck by a falling tree as he was repairing a power line.

That brings the storm's death toll up to at least three people. A snowplow driver in Kansas was killed Saturday when the plow he was driving rolled over on a highway.

Meanwhile, frigid air and high winds are causing dangerous travel conditions throughout the eastern U.S.

The National Weather Service forecasts Monday's temperatures will be more than 20 degrees (minus-7 Celsius) below normal across the Northeast, with gusty winds and wind chills approaching minus 40 degrees in northern New York and Vermont.

The bitter cold is expected to stymie travel once again with FlightAware reporting nearly 280 flights canceled as of Monday morning.

Another storm system is already developing over the Rockies that could blanket the same region with more snow by the end of the week.