SUSPICIOUS: Lismore cathedral fire was deliberately lit
UPDATE, 12.15pm: THE fire at the St Carthage's Cathedral in Lismore has been brought under control.
Lismore Fire and Rescue incident controller Brad Harrison said about 40 firefighters were the scene, including a 35m Bronto skylift from Queensland Fire Emergency Serviced Bilinga on the Gold Coast.
The skylift will allow them to monitor the situation on the roof of the cathedral.
Mr Harrison said the "damage is severe but not extensive."
It is understood the SES will this afternoon work to cover the roof.
UPDATE, 8.40am: FIRE crews are still desperately trying to bring the Lismore cathedral blaze under control.
When firefighters arrived at the scene this morning, they found large volumes of smoke coming from the roof of the building.
"Firefighters gained access and quickly extinguished an initial fire, but the blaze has spread to the rear of the property and into the roof," a NSW Fire & Rescue spokesperson said.
"Crews are currently working to contain the spread and extinguish the blaze.
"The school next door has been closed while the incident continues.
"All occupants were able to self-evacuate from the building."
UPDATE, 8.20am: POLICE are now investigating the blaze at St Carthage's Cathedral in Lismore.
NSW Fire and Rescue are still working to extinguish the blaze, which has caused significant damage to the building.
No one was inside at the time.
Officers from Richmond Police District are investigating the circumstances surrounding the fire, which is being treated as suspicious.
Police are urging people to avoid the area.
UPDATE, 7.55am: A FIRE at the Lismore Catholic cathedral is being treated as suspicious.
Richmond Police District Superintendent Scott Tanner said the blaze at St Carthage's in Leycester St started around 6.30am.
"The area is being treated as a crime scene and the state arson squad have been contacted," he said.
"A passerby noticed smoke coming out of the roof and a patrol attended along with Fire & Fire, Ambulance NSW and police rescue."
Original story: FIREFIGHTERS have been battling to save St Carthage's Cathedral in Lismore this morning.
A spokesman from NSW Fire & Rescue said the blaze broke out in the roof of the building.
"Crews believe they have found the initial source," he said.
"Power has been isolated ... it appears the fire has been able to be contained in the roof."
NSW Fire & Rescue's duty inspector has now arrived on the scene.
According to Live Traffic NSW, traffic is affected on Dawson St between Leycester St and Brunswick St
The road is closed in both directions.
Transport for NSW and emergency services are on scene.
Local diversions are in place, but these local diversions are not suitable for B-doubles. B-doubles should use the Bruxner Hwy as an alternative route.
Trinity Catholic College principal, Brother John Hilet, said: "Due to the ongoing situation with the fire at the cathedral the College will be closed for lessons today.
"If possible please keep your children at home.
"If you are unable to keep your children at home supervision will be provided on the St Joseph's site.
"Access to SMS is closed for the whole of the day."
Richmond Police District says as well as Dawson Street, road closures are in place at Orion St and the area in front of the cathedral.
There will be no parking available on Orion Street.
"Police are urging commuters to avoid this area where possible," the police district posted on its Facebook page.
"Students/parents of St Carthage's and Trinity College will be notified via school websites."
According to the Lismore Diocese website, St Carthage's Cathedral is "Lismore's most notable building".
It was designed in the Gothic Revival style of the 19th century.
The foundation stone was laid in 1892, but the financial recession of the 1890s delayed construction for 12 years.