We investigate the dynamic fracture of a close-packed monolayer of particles, or particle raft, floating at
a liquid-gas interface induced by the localized addition of surfactant. Unusually for a two-dimensional
solid, our experiments show that the speed of crack propagation here is not affected by the elastic
properties of the raft. Instead it is controlled by the rate at which surfactant is advected to the crack tip by
means of the induced Marangoni flows. Further, the velocity of propagation is not constant in time and the
length of the crack scales as t
3=4. More broadly, this surfactant-induced rupture of interfacial rafts suggests
ways to manipulate them for applications.