Two electricians are still fighting for their lives in hospital after an explosion at a Perth shopping centre that killed two of their colleagues.

The four workers were carrying out maintenance near an electrical transformer at Perth’s Morley Galleria shopping centre on Tuesday morning when the explosion happened.

Irish national Alan Cummins, 30, died at the scene.

• Two dead in WA shopping centre blast

Witnesses saw the three other men running from the building on fire.

Several bystanders came to the aid of the workers, using anything they could to douse them with water.

The three injured men were taken to Royal Perth Hospital in a critical condition with serious burns, but 22-year-old Matthew Hutchins died soon after.

He had burns covering 80 per cent of his body.

A 50-year-old man and a 48-year-old man remain in a critical condition.

High Energy Service Pty Ltd, a privately owned company that services the high voltage electrical industry, said the four men were their employees and subcontractors.

“This is a truly tragic day and our thoughts and prayers are with the family and friends of the deceased persons, and those of the injured employees,” the company said in a statement on Tuesday.

“We will be fully co-operating with all the relevant authorities in their investigations and will be conducting our own investigation.

“Our focus at this moment is supporting those injured people and their families and our other employees.”

The exact cause of the explosion is unknown, but lightning has been ruled out.

EnergySafe and WorkSafe are investigating.