OK, so I presume you’re adding in the Canadian fireworks explosion.
If you are looking at ALL types of industrial explosions WORLDWIDE, then yes, three “large” ones (depending on your definition) in a few months is certainly normal.
From Wikipedia:
May 4, 1988: PEPCON disaster in Henderson, Nevada. Massive explosion at a chemical plant killed 2 people.
May 5, 1988: Norco, Louisiana, Shell Oil refinery explosion after hydrocarbon gas escaped from a corroded pipe in a catalytic cracker and was ignited. Louisiana state police evacuated 2,800 residents from nearby neighborhoods. Seven workers were killed and 42 injured. The total cost arising from the Norco blast is estimated at US$ 706 million.
July 6, 1988: Piper Alpha disaster. An explosion and resulting fire on a North Sea oil production platform kills 167 men. Total insured loss is about US$ 3.4 billion. To date it is rated as the world’s worst offshore oil disaster in terms both of lives lost and impact to industry
I’m aware of those incidents. So exactly when will you be rubbing your chin saying “hmmm” instead of proclaiming nothing to see here folks? And exactly when will you be satisfied that they have exceeded the statistical noise?