The fire, which caused no injuries, occurred around ten minutes to six in the afternoon in some paper reels stored outdoors at a Smurfit Kappa Nervión facility, located in the Arriandi nucleus. According to data provided by the council, nearly 50 reels were burned, leading to the dispersion of small paper fragments.

The Department of Health of the Basque Executive dispatched a mobile unit for risk analysis and detection, whose results, as explained by the City Council, were "correct." This Saturday, a new measurement was conducted, confirming that "everything is correct" and that "parameters have decreased" due to rainfall, ensuring "no risk to the population".