During inspection rounds inside a petroleum depot during stormy weather conditions, an employee received an electrical discharge. A medical exam revealed a mark on the right hand, accompanied by chest pains and numbness in the right arm.
Several hypotheses were forwarded to explain the symptoms: lightning, electrical short in the depot, faintness due to cardiac troubles.
The immediate measures adopted were: restricted access to the incident zone for the remainder of the night, disconnection of all electrical outlets located near where the short circuits occurred, and remote monitoring by the site security company. On the next day, the fire automation systems on the manifold were tested under remote control conditions and revealed no anomaly. An indirect electric shock due to a recent thunderstorm event was considered the most credible hypothesis, as confirmed by recordings of lightning impacts less than 4 km away at the time of this injury, in addition to the recording that a neighbouring installation had to switch onto a backup electrical system. This shock may have been facilitated by the umbrella and may have multiple sources: transmission of electrical potential by the adjacent railroad track, or the “electrification” of ambient air.
After this incident, the site operator took a number of measures, including the restriction of vehicle traffic in the event of a thunderstorm, applicable to all those present onsite (depot personnel, subcontractor employees, visitors). The warning of upcoming electrical storms would be sounded by the lightning detector alarm and then corroborated by visual inspection. The use of umbrellas onsite would also be prohibited.