"THIS could have been the biggest disaster Rocky has seen for a long time."

Those were the chilling words from Acting Detective Inspector Paul Elliot as he explained how a man set a petrol station alight on Wednesday night.

William Mason allegedly approached a servo on Musgrave St at 10.45pm and used the nozzle from a bowser to pour petrol over the concrete floor and sidewalk.

"As the fuel came out he then lit it which ignited the petrol on the ground and he took another nozzle out and lit that one," Act Det Insp Elliot said.

If it wasn't for the quick action of the console operator and passers-by, the night could have ended in tragedy.

Act Det Insp Elliot said the bowsers were immediately shut down after the ignition which caused a significant explosion.

"There's no damage to any property or anyone injured but this had the potential to go really bad," he said.

Mason appeared dishevelled when he faced Rockhampton Magistrates Court yesterday morning on a charge of endangering by fire.

Mason sat silently in the dock as he was told he would be remanded in custody as his matter was adjourned until November 25.

Act Det Insp Elliot has praised those who helped at the fire.

"Every action when people decide to take something on themselves they have to be made on their merits, it's evident these people made an assessment that they could handle this situation," he said.

"Once the ignition source was taken away from the fire, it died down quite quickly.

"The potential for a catastrophic event was real."