Four people were killed and at least 35 more were injured after a tornado hit the US Midwest, Iowa authorities said on Wednesday. The tornado hit town of Greenfield, south-west of Des Moines, on Tuesday afternoon, the Iowa Department of Public Safety said in a statement. “The number of those injured is likely higher, but these numbers reflect only those patients treated for their injuries at designated alternate care sites,” the statement continued. The National Weather Service (NWS) Des Moines put the intensity of the tornado at EF-3 on a scale of 0 to 5 on the Fujita scale. The scale measure…