East Hartford Fire Capt. Ken Beliveau said the broken fire hydrant sent a geyser of water 25 feet into the air and the flood of water compromised the surface under the vehicle while firefighters rescued the unidentified woman, The Hartford (Conn.) Courant reported Wednesday.
"We started to move a little quicker," he said.
Assistant Fire Chief William Perez said the woman was taken to Hartford Hospital in stable condition.
Beliveau said the 4-foot-deep sinkhole swallowed the back end of the woman's Hyundai after she was pulled from the car. The vehicle was towed from the hole a few hours later.