Rescue workers helped free a woman from the rubble of her home in Greenfield, Iowa, after a deadly tornado ripped through the town on Tuesday, May 21.Video captured by Aaron Payzant and Logan Howard shows emergency responders pull a woman from her basement after her house collapsed during the storm.National Weather Service officials on Thursday identified EF4 damage from the tornado in Greenfield and said further refinement is possible in the coming days.The powerful tornado flattened buildings, flipped cars, uprooted trees, and downed power lines, according to local reports. Iowa State Patrol said that at least four people were killed in the storm. Credit: Aaron Payzant & Logan Howard (Out Off The Trail) via Storyful