Illegal "<a href="//commons.wikimedia.org/wiki/Firestop" title="Firestop">Firestop</a>", made of crud, polyurethane foam and old rubber boots shoved in the hole. A true classic in fire protection history.
<a href="//commons.wikimedia.org/wiki/User:Achim_Hering" title="User:Achim Hering">Achim Hering</a>
2007-06-18
<span class="int-own-work" lang="en">Own work</span>