A massive storm is bringing yet more ice to the Midwest today, leaving schools and airports closed and hundreds of thousands without power. At least 22 deaths, most of them in traffic accidents, are being blamed on the storm Officials in Missouri, Kansas and Oklahoma have declared states of emergency. And President Bush declared an emergency in Oklahoma on Tuesday, ordering federal aid to supplement state and local response efforts. Heavy ice and falling branches have been snapping power lines across the region. More than half a million homes and business in Oklahoma are without power and most school districts in the state remain closed for a second day. A power company spokesman says it could be 10 days before they are able to restore power to everyone. Utility companies in Missouri, Kansas and Iowa are also reporting tens of thousands of customers without power. In Iowa, Des Moines' airport was closed yesterday and a spokesman says it could stay that way, with crews unable to keep up with the ice and freezing rain. That's putting a crimp in presidential campaigning, with Republican Mike Huckabee and former President Bill Clinton canceling appearances today. Iowa's largest school district closed for the day in Des Moines, telling its nearly 31,000 students to stay home, and kids across most of Oklahoma and in the Kansas City, Mo., area stayed home for a second day. Schools also were closed in parts of Wisconsin, including Milwaukee Public Schools with 85,000 students. "We thought about our kids on foot," said Milwaukee schools spokeswoman Roseann St. Aubin. Some drivers couldn't even get to their buses, she said. About an inch of ice was expected Tuesday over parts of Iowa, followed by up to 5 inches of sleet and snow. "It's a pretty good ice-maker," said Frank Boksa, a National Weather Service forecaster. Ice as much as an inch thick had accumulated on trees, power lines, streets and car windshields Monday in parts of Oklahoma and Missouri, with thinner layers elsewhere. Nearly 600,000 Oklahoma homes and businesses still had no electricity Tuesday, most of them since Monday when power lines began snapping under the weight of ice and falling branches - the biggest power outage in state history. Utilities in Missouri reported more than 100,000 homes and business without power and Kansas utilities said probably more than 70,000 were blacked out Tuesday, with some in the dark since Sunday. "This is a big one. We've got a massive situation here and it's probably going to be a week to 10 days before we get power on to everybody," said Ed Bettinger, a spokesman for Public Service Company of Oklahoma. "It looks like a war zone." Iowa's two major utilities reported over 17,000 customers without power Tuesday. Many travelers also were grounded at Chicago, where about 250 flights were canceled Tuesday morning at O'Hare International Airport and departure delays averaging 15 to 30 minutes, said Karen Pride of the city's Department of Aviation. Kansas City International Airport in Missouri canceled more than 90 flights Tuesday morning, but spokesman Joe McBride said that was probably due to problems at other airports. The Federal Emergency Management Agency and the Army Corps of Engineers sent 50 generators and three truckloads of bottled water from Texas to distribute to blacked-out areas of Oklahoma. At least 22 deaths - most of them in traffic accidents - had been blamed on the ice and cold since the weekend, including 15 in Oklahoma, four in Kansas, and three in Missouri.