Two volunteer firefighters died when their truck rolled as they were fighting bushfires south-west of Sydney.

Deputy Captain Geoffrey Keaton and firefighter Andrew O’Dwyer from Horsley Park Brigade were battling the Green Wattle Creek blaze at Buxton when their truck hit a tree just before midnight on Thursday.

The tree subsequently fell on the rolled truck, crushing the cabin and killing its occupants.

Police say the truck appears to have travelled out of control for a short distance before rolling over, and investigations are continuing.

Three of their colleagues in the back of the truck were injured and transported to Liverpool hospital.

The NSW Rural Fire Service said the vehicle was travelling in a convoy during firefighting operations when it hit the tree.

“The Service’s thoughts are with all the firefighters’ family, friends and fellow brigade members,” it said.

The 2 firefighters killed in a vehicle accident last night are Deputy Captain Geoffrey Keaton 32yrs & Firefighter Andrew O’Dwyer 36yrs, both from Horsley Park Brigade. Our thoughts are with their family, friends & fellow brigade members. #nswrfs pic.twitter.com/p3Y8zX3hBj

— NSW RFS (@NSWRFS) December 19, 2019

Two other firefighters have been placed in induced comas in hospital after suffering burns in a separate incident yesterday afternoon.

NSW Emergency Services Minister David Elliott tells John Stanley the young families of the volunteers have been notified.

“It’s a tragedy.

“The entire firefighting fraternity will be in mourning today.

“My condolences to the families and we’ll make sure that they’re wrapped around with a blanket of love.”

Click PLAY below to hear the full interview

Image: Twitter/NSW RFS