In fairness, that isn't the "wing" strictly speaking, it is the winglets. It is designed to reduce drag by stopping vortex from forming at the end of the wind rather than to provide lift within its own right.

If one fell off or broke for example it is unlikely to cause a fatal accident unless during takeoff/landing or if it damaged some other vital system. The pilot might have to increase engine power and compensate for the aircraft losing its equilibrium.