The incident happened Wednesday on Fieldstone Lane in the Country Creek community of Newark, the New Castle County Division of Police said.
Bodycam video shows the woman’s left arm and leg pinned under the vehicle’s front left tire, while her right leg was stuck in the wheel well.
Before officers arrived, police said a neighbor had tried to lift the SUV using a jack, but the jack was too short.
The good Samaritan, identified as Kyle Stant, told WPVI-TV he "did everything in my power" to help his neighbor.
"She said, 'Kyle, please help me, don't leave me' and I told her, ‘I am not going to leave you,'" Stant said. "’We are going to get through this. We are going to get you out.’"
Video shows Stant and four officers lifting the vehicle high enough so that a fifth officer could pull the 70-year-old out from under the wheel.
Police said that woman was treated for injuries at a local hospital.
Mark Logemann, chief of the New Castle County Emergency Medical Services Division, praised Stant and the officers for their heroic actions.
"The quick thinking and physical actions of the bystander and the officers from the Division of Police played a major role in this patient being protected from further injury and possibly death," Logemann said.
Police told WPVI that the woman had forgotten to put the vehicle in park when exiting and got stuck underneath when the vehicle rolled.