The site, classified as SEVESO II (European legislation on major hazards), is entirely devoted to assembly work on pyrotechnics. The process is divided up between some thirty small buildings, which is normal for this type of industry. Certain areas are reserved for the pyrotechnical machines. The land is entirely fenced in and isolated from any other businesses. Site operations mainly take place from 7:30 a.m. to 4 p.m., Monday-Friday. Nevertheless, two security guards are present 24/7 at the guard station where all of the fire and intruder alarms go off.
On a Wednesday, at around 5 a.m., an alarm goes off at the guard station, stemming from a sprinkler system in a building devoted to pyrotechnical work, approximately 2,000 m2 in surface area. At that very moment, one of the security guards is doing monitoring rounds on the site. Alerted by his colleague at the guard station, he immediately goes to the location in question. He there finds that a utility room is completely filled with smoke and that a sprinkler head has been triggered. The sprinkler alarm triggered automatic shutdown of the utility installations (4 air handling units) and simultaneously closed the fire dampers in the air ducts.
The 64 m2 utility room had a 2-hours fire cutoff rating. The pass-throughs for cables, ducting and other services were completely sealed off using fire cutoff materials with specifications similar to those of the walls. The equipment contained in the room was as follows: air handling units (HVAC), electric distribution cabinets, inverters, power cabinets, humidifiers, building management systems (BMS), etc.
An entry opening detector and a motion detector are also installed at that location. At the same time, the security guard at the guard station followed the prescribed emergency procedures:
- 5:12 a.m.: He called the internal emergency crew and
the fire department, as well as site management. Once
on site, the emergency action crew shut off electric
power to the building and found that the initial fire had
been put out by the sprinkler system
- 5:35 a.m.: By the time the fireman and the General
Manager arrive, the risks are under control. A joint
decision is made to close off the control valve for the
sprinkler system in question, but the remaining sprinkler
systems are left in operation. The fire department then
- 6:15 a.m.: The on-call maintenance crew shows up at the site
- 7:15 a.m.: Directions are given to limit communication of the incident to the outside
- 8 a.m.: The utility room is returned to operation after isolating the damaged air handling and humidifying systems. When they arrive for work, the employees find almost normal operations under way
- 3:00 p.m.: The sprinkler system in the damaged area is repaired on and the control valve for the sprinkler system in question is re-opened