What happened?

Don't worry, Lyon wasn't struck by an earthquake today...
This is an art installation by Lucie Lom, two graphic artists/scenographers, on the occasion of a street art festival in Villeurbanne, suburb of Lyon. Many kinds of events during four days and evenings : street theatre, art installations, concerts, and more. Always very inventive, the only shame is that it only takes place from Wednesday to Saturday... all working days for me, so I'm missing most of it.