Chicago , Illinois ( CNN ) -- Severe overnight storms in the Chicago area caused power outages , flight cancellations and flooded homes and roadways . About 50,000 ComEd customers were without electricity Saturday morning after lightning and heavy downpours pummeled the city overnight , said Laura Micheli , a spokeswoman for the utility . It was unclear when power would be restored to those households because storms were still rolling through the area , she said . The outages started at about 6 p.m. ( 7 p.m . ET ) Friday night . CNN iReporter Nancy Holst of Lombard said her husband , who is a firefighter , responded to several calls overnight where he was working in waist-deep floodwaters . She said he took one look at her once-blooming garden now sitting under 6 inches of water and said , `` That 's nothing . '' The storms caused damage through Chicago suburbs before moving into downtown in the morning , she said . The bad weather also forced the cancellation of 200 flights at the Chicago O'Hare International Airport Saturday morning , according to Karen Pride of the Chicago Department of Aviation . There were delays of up to one hour at the airport at midday , she said , but no delays were reported at Midway International Airport . Pride said there was some airfield flooding at O'Hare Friday night , but flight operations were not affected . The National Weather Service in Illinois reported that at least 6.3 inches of rain fell at O'Hare and 6.2 inches at Midway . CNN affiliate WGN reported more than 5 inches of rain were dumped over some parts of the Chicago area Saturday morning . There were also reports of flooded basements and expressway closures . A flood warning remained in effect for parts of the region until 7 p.m. ( 8 p.m . ET ) . CNN 's John Branch contributed to this report .
NEW : A tornado warning remains in effect until 5 p.m . Severe storms have caused residents to lose power in Chicago . The storms have moved into downtown . Flooding has forced officials to close some roadways .