The remnants of the chaotic situation that unfolded earlier this morning remain along the now eerily quiet George Street.
Investigators are currently accessing the scene, while emergency services are trying to clear the damage.
Though the road is likely to be closed for some time.
The Westpac Rescue Helicopter is transporting a 67-year-old male from Singleton to John Hunter Hospital suffering multiple injuries sustained in this serious incident.
A critical incident investigation has been launched following a truck crash at Singleton.
A second helicopter from Sydney has been tasked to the scene to assist.
Just before 7.30am today (Wednesday 11 October 2017), police responded to reports of a semi-trailer stolen from a service station at Murrurundi in the Hunter Valley.
The truck was allegedly sighted driving erratically south along the New England Highway, through Muswellbrook and towards Singleton.
A pursuit was not initiated.
As the truck approached Singleton, officers deployed road spikes in order to stop the vehicle.
The truck continued into George Street, Singleton, where it caught fire after crashing into several vehicles and buildings, injuring a number of people.
A man in a vehicle was taken to John Hunter Hospital in a critical condition.
The driver of the alleged stolen truck was arrested at the scene and is currently assisting police with inquiries.
A critical incident team from Port Stephens Local Area Command will now investigate all circumstances surrounding the incident including the deployment of road spikes.
That investigation will be subject to independent review.
No further details are available at this time; however, police are appealing for witnesses to come forward.
The truck owner has told The Singleton Argus that the truck was stolen this morning from the BP at Murrurundi while the owner was paying for fuel.
The truck was on its way to Tamworth loaded with mushroom compost, collected earlier from Windsor.
Once stolen, the driver headed south down the New England Highway before being caught and arrested by police in George Street, Singleton.
The New England Highway is closed in both directions in Singleton due to a truck crash and police operation at Kent Street.
Southbound motorists are being diverted onto Lemington Road in Ravensworth and onto the Golden Highway to Whitttingham.
The northbound diversion is the same in reverse.
Motorists already in the area should allow plenty of extra travel time as traffic is heavy.
Emergency services and traffic crews are on site and crash investigators are attending.
The highway is expected to remain closed for several hours.
The Westpac Rescue Helicopter has been tasked on a primary mission to a multi-vehicle accident on the New England Highway in Singleton township.
More details to follow.
Emergency services are now on the scene at a multi-vehicle accident that has occurred near Burdekin park this morning.
The accident has resulted in flames, with major traffic delays expected.