A woman was killed and three people were injured when a stolen lorry ploughed into the side of a house.
Police were called to Park View, in Brierley, Barnsley, at about 13:40 BST, after the HGV crashed into the house.
A senior officer confirmed to the BBC the woman who died was a pedestrian. No details have been released about the injured people, who have been taken to hospital.
Four men had been arrested in connection with the crash, police said.
A South Yorkshire Police spokesman said an officer in a marked patrol car was following the stolen lorry when it hit the woman, aged in her 50s, before crashing into two cars and the house.
Video footage has emerged which appears to show two young men getting out of the lorry before running away.
Officers at the scene said the lorry had been "involved in crime" before the crash.
The Independent Office for Police Conduct confirmed it was investigating.
South Yorkshire Fire and Rescue said three fire engines, including one from West Yorkshire, were sent to the scene.
Park View is currently closed from the junction of Common Road and delays to bus services have been reported as a result of the crash.
Witnesses said no-one was inside the semi-detached home at the time of the crash, but its occupants returned home after it was struck.
One passerby said the lorry "was obviously going too fast" and had "hit two cars and then just crashed right into the house".