Most observers date the phenomenon to an Italian teen novel titled "I Want You, " published in 2006, featuring two Roman lovers who immortalized their bond on a bridge in the Eternal City and threw the key in the Tiber.
When suicides are dredged from the Seine, it is said, the lovers and the debtors are easy to tell apart: the lovers have paint under their nails, from trying to claw their way back on to the bridge at the last moment, whereas the debtors sink like stones.
Some structures simply can't support the bulk of 1, 000 lovers' dreams, so every now and then sparks fly in Seville as angle grinders sweep the bridge clean.