On the evening of 20 July, chaos erupted at the Place Guillaume II underground car park in central Luxembourg City, where it took several hours for people to exit with their vehicles after a fire alarm triggered the automatic closure of security doors.
The alarm went off around 7pm, causing the security doors to close and block access between the various floors of the car park, preventing cars from leaving. Many people expressed frustration as they found themselves "trapped" within the facility.
Luxembourg City Mayor Lydie Polfer has now explained the cause of the alarm, attributing it to "a fault in the heat-sensitive cable detector, specifically a disturbance in the ohmic value of the detector." In response to question from Green Party local councillor Nicolas Back, she emphasised that it was a false alarm and assured the public that "there was never any risk to the people inside."
Mayor Polfer also clarified that at no point were people physically trapped inside the car park. The five stairwells remained accessible at all times, although the affected individuals refused to use them despite police requests.
Some people also stayed in their cars with the engines running, but Polfer noted that this did not pose a danger, as carbon monoxide levels remained low throughout the incident.
The situation was eventually resolved, but not without delay. The initial alarm was triggered at 7.09pm on level -3 of the car park, and the fire doors in the traffic ramps were not electronically reopened until 9.37pm.
According to Mayor Polfer, the car park attendant was unable to manually deactivate the alarm and had to call a technician. The technician, delayed by a "motorway closure," arrived on the scene around 8.35pm and was able to resolve the issue.
