Two men remain in hospital this morning after they and nine others were struck by lightning in the Northern Goldfields when a severe thunderstorm hit the region on Saturday.

The 11 men — which comprised eight labour hire contractors and three Arc Infrastructure employees — were taken to Leonora Hospital immediately after the lightning strike. Five of them were sent home straight away and two were kept for observation before being released later on Saturday.

The remaining four were flown to Kalgoorlie Hospital via the Royal Flying Doctor Service, according to the WA Country Health Service, with two discharged at 9.40pm on Saturday night and the other two to be kept for observation and likely to be released on Monday.

The Arc Infrastructure employee and labour hire contractor still in hospital were expected to make a full recovery.

It is understood the men were working outdoors on a rail line north of Kookynie when they were struck. Arc Infrastructure said in a statement a full investigation into the incident was underway.

“Our focus in the last 24 hours has been on ensuring these people have received the right medical attention they need and their families are well informed and supported,” Arc Infrastructure said.

The WACHS spokeswoman, while not able to detail the men’s exact injuries, said muscle fibre degeneration often happened as a result of being struck by lightning and it was likely doctors needed to make sure the men’s heart and kidneys were functioning properly before they were able to be released from hospital.

“Lightning strikes can affect the heart, affect kidney functioning, it can make limbs weak, cause general malaise and headaches, loss of consciousness,” she said.

“In some cases it can cause burning or affect one’s hearing. In rare cases it can cause death.

“In the case of muscle fibre degeneration, it’s important doctors observe the patients to make sure all their vital organs are functioning properly.”

The severe storm prompted a warning from the Department of Fire and Emergency Services on Saturday afternoon.

It advised those living in Kalgoorlie, Carnegie, Laverton, Leinster, Leonora and Menzies to take precautions to stay safe.

Bureau of Meteorology WA duty forecaster Catherine Schelfhout said this weather was not unusual for inland parts of the State this time of year.

She said the thunderstorms, which occurred often during the summer, could damage homes and make travel dangerous.

DFES has advised people in the Goldfields area over the next few months to continue to be aware of, and careful of, thunderstorms.

“If outside, find safe shelter away from trees, powerlines, storm water drains and streams,” the warning said.

“Close curtains and blinds, stay away from windows and unplug electrical appliances. If there is flooding, create your own sandbags by using pillow cases filled with sand and place them around doorways to protect your home.”