The Astonishing Theory Behind The 1942 ‘Miracle Bomb’

Was it divine intervention or Czech sabotage which saved 300 Maltese lives?

Mirek Gosney
Lessons from History
8 min readMay 19, 2021


Photo of a replica of a 500kg SC bomb on display inside Mosta Dome, circa 2016. Image Credit: Mirek Gosney.

The British colony of Malta was essential to the Allied victory in the Mediterranean during the Second World War. It protected Allied supply lines and targeted Axis convoys passing between North Africa and Sicily.

But this strategic importance came at a cost. The isolated archipelago was subjected to a gruelling three-year siege, which included relentless bombing campaigns by the Luftwaffe and the Regia Aeronautica (Italian Air Force).

The unprecedented destruction and loss of life was unimaginable and led to Malta becoming the most bombed place on Earth.

Yet, one bomb continues to be of special interest almost eighty years later.

The Bombing Of Mosta Dome

Photo of Mosta Dome located in the town of Mosta, Malta, circa 2016. Image Credit: Mirek Gosney.

On 9 April 1942, two enemy aircraft headed or retreating from RAF Ta ‘Qali jettisoned their bombs over the nearby town of Mosta.

One bomb struck the Rotunda of Mosta, or Mosta Dome, a spectacular Roman Catholic church and universal icon of Malta. At 16:00, 300 parishioners had congregated inside the Church for evening mass.

At this point during the ‘Second Siege of Malta’, church bells sounded to warn of incoming air raids while sirens signified the ‘All-Clear’. Some parishioners fled to nearby bomb shelters, while the majority chose to hide within the side chapels.

At 16:40, a 500kg SC (a thin-cased demolition bomb) penetrated the ceiling of the dome and landed inside the Church. It failed to explode. With no causalities, the stunned parishioners rushed for the exits.

Map of wartime Malta. Image Credit: UXB Malta (2012), courtesy of S A M Hudson.
Photos of Lt. Thomas Blackwell (left), and Lt. George Carroll (right). Image Credits: UXB Malta (2012), courtesy of S A M Hudson.

One of the two Royal Engineers Bomb Disposal Officers (BDOs) serving in Malta in 1942 was responsible for defusing the bomb. Lt. Thomas Blackwell and Lt. George Carroll led Bomb Disposal (BD) Sections No. 127 and No. 128 respectively.

The unexploded bomb (UXB) was a ‘Priority’, meaning that it required urgent attention. Exploding the bomb in situ was not an option, due to its location in a site of significant cultural value.

There was also the alarming prospect that the bomb was fitted with a delayed-action (DA) Type 17 Clockwork Fuse (a time bomb). These would detonate anywhere between two to eighty hours after impact. It could also contain a Type 50 Anti-Handling Fuse (a booby trap), which would detonate on the slightest disturbance. Further reasons why it needed to be defused right away.

Fortunately, the bomb was a general-purpose (GP) high explosive (HE) bomb fitted with a straightforward Series 5 Electric Impact fuse. Its thin-casing ensured that it only embedded itself four feet below ground level on impact. Had the bomb travelled further, this would have demanded a more extensive and dangerous excavation.

The BDO defused it and compiled their report, marking the bomb as ‘defused and removed’. This was filed under UXB report No. 2175 and attached to the section’s official War Diary, a mandatory requirement within the Military.

The report also included a 50kg SD (a thick-cased fragmentation bomb) that had bounced off the dome’s exterior and landed nearby. This was also discharged without issue.

Both bombs were then transported to the west coast, somewhere between Dingli and Hal Far, and dumped into the sea.

The entire ordeal helped to affirm the faith of the deeply religious Maltese, who later hailed this as ‘Il-Miraklu tal-Bomba’, or ‘The Bomb Miracle’.

Yet, another theory maintains to know the real reason why the Mosta bomb failed to explode.

From Pilsen With Love - The Czech Sabotage Theory

Photo of the assembly of the first gun turret for the Austro-Hungarian battleship, ‘SMS Viribus Unitis’ at the Škoda Works in Pilsen, circa 1909. Image Credit: Public Domain.

Another potential theory explaining why the Mosta Bomb failed to detonate claims that industrial sabotage by Czech forced labourers was responsible. Instead of Amatol explosive, sand was discovered inside the bomb along with a note reading ‘Greetings from Plzeň’.

Nazi Germany occupied Czechoslovakia in March 1939, after which time the Škoda Works armaments factory in Pilsen became vital to the Axis war effort. The factory relied on conscripted Czech labourers to function once its German workforce was redeployed to the frontlines.

Sabotage here became well documented within the Protectorate and abroad. Any workers found guilty of committing acts of sabotage risked summary execution or deportation to concentration camps.

Newspaper excerpt about Czech sabotage at the Škoda Works, circa 19 April 1943. Image Credit: Nelson Evening Mail / CC BY-NC-SA 3.0 NZ.

The resistance activities of the Škoda Works even formed the plot of the British espionage thriller, The Adventures of Tartu (1943), shown to the Czech President in exile, Edvard Beneš in London.

The passive defiance of these brave men and women remains a source of national pride for many Czechs. A keen believer in the sabotage of the Mosta Bomb is Martina, a Czech expat living in Malta since 2007.

‘ I like to believe [the Czech sabotage theory] is true and I do enjoy telling the story to my friends and family visiting Malta.

[The Czech sabotage theory] was actually mentioned in one of the Czech language guides about Malta. ‘

Photo of Albert Göring, circa 1936. Image Credit: Wikimedia Commons / Fair Use.

Also interesting is that Albert Göring worked as the Export Director of the Škoda Works from June 1939. He was the younger brother of high-ranking Nazi, Hermann Göring, the Commander in Chief of the Luftwaffe.

Unlike his devout Nazi brother, Albert was an outspoken anti-fascist.

Exploiting his brother’s influence, he routinely undermined the Nazi regime. Some of the ways he achieved this were by colluding with the Czech resistance and by supposedly encouraging acts of sabotage at the Škoda Works.

Although, no evidence exists to link Albert Göring to the alleged sabotage of the Mosta bomb.


Does the Czech sabotage theory warrant any serious consideration?

It is impossible to answer this question without encountering a range of issues. These are as follows.

Who Worked on the Bomb?

The first difficulty is identifying which of the two BDOs defused the Mosta Bomb. Their testimony would be the most qualified for detecting any signs of sabotage.

Useful to consider is that only the BDOs handled bombs of 250kg and over. BD procedure further stipulated that only individuals essential to a UXB’s defusal should be present, while everyone else must evacuate to a safe distance.

So, it is plausible that only the BDO was present with the bomb inside Mosta Dome. Yet, this still does not help to confirm which BDO this was, as BDOs were not required to sign their UXB reports.

After 23 April 1942, BD operations were divided across geographic lines with section No. 127 becoming responsible for UXBs in the south, while section No. 128 handled those in the north. This future development would have made it far simpler to determine which BDO dealt with the Mosta Bomb.

Instead, the bombing of Mosta occurred during the most intense period of saturation bombing witnessed throughout the entire siege, meaning that BD records were even more sparse than usual. No weekly BD reports were submitted between 21 February and 27 March.

In April 1942 alone, 6,728 tons of explosives were dropped on Malta. These claimed many lives and devastated various historic landmarks. It is no surprise then why the Maltese perceived the Mosta Bomb as a miracle.

Photo of the Royal Opera House located in Valletta, the capital of Malta, following an air raid, circa 7 April 1942. Image Credit: Imperial War Museums / IWM Non-Commercial Licence.

Evidence Of Sabotage

Another outstanding question is how apparent evidence of sabotage would be to the BDO. The thin-casing of an SC explosive could have split open on impact, though this is unlikely.

British historian, Susan Hudson, author of UXB Malta and daughter of the late Lt. George Carroll, explores another possibility.

‘ If the fuse had been operational, but the bomb casing filled with sand, the detonation of the fuse and that of its explosive gaine would likely damage the bomb casing sufficiently for the filling to be exposed as sand. ’

Yet, the Mosta UXB report contained no mention of a split or damaged casing.

Diagrams depicting the anatomy of an SC-500 bomb (left), and a German electronic bomb fuse. Image Credits: Cyberwar Before there was Cyber, Hacking WWII Electronic Bomb Fuses (2017), courtesy of Peter Gutmann of the University of Auckland.

Though records were vague, BDOs were obligated to log any anomalies in UXB reports. These were then forwarded to the War Office and circulated across BD Sections in Britain and other Allied territories to discover whether they had encountered something similar.

The BDOs active in Malta were highly knowledgeable and experienced, so there is very little doubt that they would have omitted such crucial information.


Much of the evidence surrounding the Mosta Bomb consists of primary testimonies, which are notorious for growing unreliable over time.

The bombing of Mosta Dome happened almost eighty years ago. All first responders and witnesses involved in the incident have now passed. But even while these individuals still lived, their recollections often became confused and inaccurate.

The Maltese historian, George Cassar, cites this factor as being the main barrier preventing researchers and interested parties from reaching a unanimous conclusion about the Mosta Bomb.


Of the 17,000 tons of bombs that blitzed Malta between 1940 and 1943, 15% failed to explode. There were many possible reasons why this would occur.

These included poor manufacturing methods, faulty components, and sheer luck. Inexperienced enemy aircraft crew would sometimes fail to arm a bomb’s fuse prior to its release. Sabotage ranked low on the list, as this was very difficult to prove.

Yet, the question remains:

Where did this theory originate to start with, and why?

Had a Czech saboteur read about the Mosta Bomb and drawn a connection with their activities? Likewise, did someone in Malta decide that foreign sabotage must be responsible?

Or, did the Maltese tourism industry invent the story to attract foreign interest? A resounding success, if this is the case. In the absence of strong evidence, all anyone can do is speculate. As the arrival of new evidence is also unlikely, the case of the Mosta Bomb is destined to remain a mystery.

Beyond any doubt, however, is what the bombing of Mosta represents for the Czech and Maltese people. Perhaps, rather than debating any physical connection between these two nations and this event, it should be commemorated as a symbol of their quiet heroism and resilience during a time of unthinkable chaos and suffering.


  • Martina Brtnická, a Czech blogger and resident of Malta since 2007.
  • Susan Hudson, a British historian and author of UXB Malta, and daughter of Lt. George Carroll.
  • George Cassar, a Maltese Historian and resident of Mosta.



Mirek Gosney
Lessons from History

Writing about Film, History, Culture & Society | British-Czech | UK Based | Writer | Filmmaker | Film Teacher | BA Film and History, University of Southampton.