While governments the world over redouble their efforts to combat modern-day terrorism, the story behind Western Australia's worst — and only — mass bombing remains strangely obscure.

Mine worker Pero Raecivich killed 14 people and wounded 15 others when he bombed a boarding house and a pub in Boulder, 600 kilometres east of Perth, on February 1, 1942.

In terms of fatalities it remains WA's worst act of individual mass murder, bearing all the hallmarks of the lone wolf-style terrorist attacks that trouble national security authorities today.

But while the story drew plenty of publicity at the time, it is now almost completely unknown outside of Kalgoorlie-Boulder.

Little chance of escaping alive

Raecivich's first target was a boarding house on Milton Street, now Davidson Street, where more than 30 people were crammed into a dining room playing dice and gambling.

With the bomb detonating in the room at 12:10am the occupants, mostly eastern European mine workers, were left with little chance of escaping alive, with seven people killed outright by the blast.

Twenty minutes later Raecivich moved to the nearby Launceston Hotel, where he had been staying, and threw a stick of gelignite into the kitchen and a second one to blow up a tank at the rear of the property.

The Launceston Hotel in Boulder in 1942. ( Supplied: Outback Family History )

City of Kalgoorlie-Boulder archivist and historian Tim Moore suggests the large numbers of eastern Europeans living at both locations may have been somewhat significant.

"You've got a lot of ties back to Croatia, Dalmatia and other places like that, all of which are under Nazi occupation," Mr Moore said.

"This bloke certainly had a gripe with what was going on, but whether that played a role in him wanting to blow everyone up, nobody knows."

Newspaper reports reveal one man, 42-year-old Kristo Kosich, survived the blast at the boarding house and staggered to the Launceston for help, only to be caught and injured in the second explosion.

Local reverend's gristly discovery

After the shock of the initial three explosions, things quietened down until 2:00am when residents reported hearing another explosion on Boulder's outskirts.

An account of the bombings, published in the Daily News in 1942. ( Supplied: National Library of Australia/Trove )

The blast's source remained a mystery until local Reverend WR Forbes travelled to the Boulder Cemetery the next morning.

"The poor vicar goes out to organise a funeral and finds [Raecivich] has blown himself up," Mr Moore said.

The blast left a foot-deep crater in the ground with the 45-year-old's remains "scattered over a 100-yard radius".

Those remains, including clothing fragments and a "distinctive black wart", helped identify Raecivich as the bomber.

While the story made headlines at the time, it quickly disappeared from public consciousness after a coronial inquest two months later.

Coroner T Ansell suggested evidence found in Raecivich's room at the Launceston may have indicated a motive.

"In all these writings, reference is made to a certain subject which had played on Raecivich's mind," he said.

"I am drawn to the conclusion they explain the reason for the bombing ... and the deaths of 14 people."

Davidson Street, formerly Milton Street, bears no signs it was the site of WA's worst bombing. ( ABC Goldfields-Esperance: Sam Tomlin )

Cryptically the coroner did not reveal the motive — something Mr Moore believes was due to the desire to protect the ongoing war effort and to prevent local unrest.

"The [Second World War] was a huge, huge issue," he said.

"The bomber was dead, they're burying the victims. The whole thing was wrapped up in a couple of weeks except for the inquest."

Police historians keep story alive

A comprehensive account of the bombings survives by virtue of the WA Police Historical Society.

President and former assistant commissioner Peter Skehan said he was not even aware of the bombings until very recently.

"I'd always prided myself on knowing the history. I was chief of the CIB for three years and had to know these things," Mr Skehan said.

"I'd worked with a chap named Mick Leeder in the 1950s, he was one of the first on the scene after the bombings but he'd never mentioned it."

A chance encounter with a retired local superintendent, Graham Lee, left Mr Skehan with a detailed story of the episode and its traumatic after-effects.

"It was his vivid memory of the truck breaking down in Hannan Street," Mr Skehan said.

"The blood was oozing out of the truck onto the road as they were trying to get the damn thing going and get the bodies to the morgue."

The approximate location of the Launceston Hotel in Boulder, now simply waste ground. ( ABC Goldfields-Esperance: Sam Tomlin )

Mr Skehan agreed that the fact the bombing occurred at the height of WWII may have played a role in its obscurity.

"There were thousands of men losing their lives overseas," he said.

"Plus the people who were killed were only known in Boulder and Kalgoorlie."

But he said it still surprised him the story was not better known.

"I don't know if we've had a tragedy as large as this in this state. I'm sure we haven't," he said.