UPDATE, 9.20AM: A police spokesman said two people were taken to Grafton Base Hospital by ambulance following a crash at the intersection of Spring and Crisp St this morning.
It is understood both injured people were the drivers of the respective vehicles.
Traffic control was in place with only minor disruptions to traffic.
ORIGINAL STORY, 8AM: There has been a two car collision underneath the viaduct near McDonald's in South Grafton this morning.
According to a witness who drove past the crash, a small blue car had the front of it smashed in while a second vehicle, believed to be a four-wheel drive, had mounted the footpath underneath the viaduct.
The witness said they were unable to see if anyone was hurt, but there did not appear to be anyone trapped inside the small blue car.
Police, fire and ambulance attended the scene, which occurred at about 8am this morning.
At the time of the incident, police were directing traffic around the scene.