A woman in her 70s was taken to hospital after a van hit a house on Thursday.
Two fire engines and ambulance crews from Hemel Hempstead, St Albans and Tring rushed to her aid after being called to Park Rise, Northchurch, at 2.45pm.
Herts Fire and Rescue Service spokesman David Henning said: “They found one vehicle in collision with a gas metre attached to a house.
“It was ruptured and we isolated the gas supply from the house.”
British Gas then came out to fix the problem.
East of England Ambulance Service NHS Trust spokesman Gary Sanderson said the woman received slight injuries after the 2.45pm smash and was taken to Watford General Hospital for further care.