  We consider two entangled accelerating qubits coupled with real scalar
fields, each described by the Unruh-Wald model. It is demonstrated that because
of the Unruh effect, the bipartite entanglement of the two qubits suddenly dies
when the acceleration of one or more qubits are large enough. We also consider
three entangled accelerating qubits in GHZ state and in W state, with equal
acceleration-frequency ratio, and found that in either state, the tripartite
entanglement suddenly dies at a certain value of acceleration-frequency ratio.
The equivalence between the Rindler metric and the Schwarzchild metric in the
vicinity of the horizon of a black hole implies that for the two entangled
qubits outside a black hole, the entanglement suddenly dies when one or both of
the qubits are close enough to the horizon, while for the three entangled
qubits in GHZ or W state, the tripartite entanglement suddenly dies when these
qubits are close enough to the horizon.
