'Stay safe out there': Crew of fallen firies return to work

The colleagues of two volunteer NSW firefighters who died when a tree fell onto the path of their tanker returned to work this morning.

Geoffrey Keaton, 32, and Andrew O'Dwyer, 36, were travelling in a truck convoy near the town of Buxton southwest of Sydney late on Thursday when a tree fell, causing the tanker to roll off the road. Both were killed.

Three other firefighters were injured but managed to free themselves from the wreckage and were later taken to hospital.

The Horsley Park Brigade in Western Sydney posted on Facebook this morning they were heading back to the fire ground in "memory of Geoff and Andrew."

"In true Horsley Park spirit, our crew are heading out today as part of a Cumberland Zone Strike Team in memory of Geoff and Andrew," the post read.

"To all crews in the field today, stay safe and look after each other."

The brigade have paid tribute to their fallen colleagues by posting stickers to the men on their truck.

Yesterday, tearful colleagues lowered flags to half-mast and the two men's helmets were put out in respect.

Geoff joined the NSW Rural Fire Service in 2006 and was the deputy captain of the Horsley Park Rural Fire Brigade in western Sydney and a former member of the Plumpton Brigade.

Andrew joined in 2003 and was also a member of the Horsley Park Brigade.

Geoff and his partner Jess have a son, Harvey, and Andrew has a daughter, Charlotte, with his partner Mel. Both children are 19-months-old and were born within two days of each other.

"They are at a loss," NSW RFS commissioner Shane Fitzsimmons said of the pair's families.

"They're in extraordinary shock and natural despair at the enormity of what's confronting them and to try and comprehend the tragedy."