Fire at a generator of a power plant

A leak of a compression fitting lead to the build up of an explosive air/hydrogen mixture in the generator pit. The ignition of the mixture was caused by corona discharge.
The resultant explosion caused substantial damage to generator and structure.
No injuries to personnel.

The INITIATING cause was a leaking fitting.
Nothing can be said on the root cause

generator

01:02 a.m. The explosion followed by fire was reported on the emergency number 112. The emergency shutdown procedure was implemented by activating the ESD system, followed by emergency depressurisation, nitrogen purging and isolation of the affected area.
01:15 External firefighters arrived onsite (4 officers and 35 non-commissioned officers, 3 fire engines, 1 CBRN, 1 tanker, 1 rescue truck, 1 first intervention and command vehicle) With the plant firefighters (12 firefighters) intervened to extinguish the fire with the powder and nitrogen truck and fire extinguishers.
The dispatcher's coordinating doctor assigned 5 SMURD(Mobile Emergency, Resuscitation and Rescue Service) and 4 SAJ(County Ambulance Service) teams to the scene of the intervention. Measurements were made by the CBRN crew and it was found that there were no leaks of hazardous substances into the atmosphere.
01:31, since there were no particular dangers and the situation was under control, a message was sent to the population to prevent panic.
02:45 the fire was extinguished.