Questions were being asked on Tuesday night about the effectiveness of a warning system set up in the wake of the 2004 Indian Ocean tsunami after Indonesian officials said an e-mailed warning about Monday’s offshore earthquake was received 14 minutes after towering waves hit southern Java.

The death toll from the latest tsunami – the result of a 7.7-magnitude earthquake in the Indian Ocean – rose to around 500 on Wednesday as rescuers continued to scour the rubble in coastal communities. But as the toll rose, observers were beginning to question the efficacy of the much-touted Indian Ocean tsunami warning network.