The incident occurred overnight from 4 to 5 December. Bolesławiec County Headquarters of the State Fire Service:
(...) at 11:58 p.m., a report was received by the Control Post of the County Commander of the State Fire Service in Bolesławiec concerning smoke in the staircase at Małachowskiego Street. The duty officer at the control post dispatched firefighters from JRG Bolesławiec.
The officers add: – When the crews arrived at the scene, it was not known what had caused the smoke in the staircase. The firefighters began checking the apartments on the ground, first, second, third and fourth floors.
At that point, one of the ground-floor residents informed them that a telephone had caught fire in his apartment. The firefighters: – The resident carried the burning telephone outside the building, filling the staircase with smoke.
And concluded:
After measurements were taken with a multigas detector in the apartment and on the staircase, no dangerous gases were detected. The smartphone was checked and showed signs of burning. The police patrol that arrived at the scene carried out explanatory activities.