The National Weather Service has greatly improved its ability to identify and warn about tsunamis, but the disaster that struck this week is a reminder that nature can prevail against any system of deterrence. The agency's Pacific Tsunami Warning Center in Ewa Beach should learn from this experience, just as it gained and applied knowledge from the 2004 Indian Ocean tsunami.

Death tolls throughout Southeast Asia and in Samoa, Tonga and American Samoa rise as more areas are surveyed, even though the warning center was quick in sending out the alarm about the oceanic earthquake with a magnitude of 8.0. The quake, located only 125 miles south of the Samoan islands, produced waves 20 feet high traveling at speeds approaching 530 mph.

No wonder, then, that the tsunami came as a shock to Samoans, since Ewa Beach sent out the first tsunami bulletin only 15 minutes after its first signs.

Less than 25 minutes are figured to have elapsed between the earthquake's occurrence and the waves that struck Samoa.

“;This is the kind of earthquake one would expect to be very destructive in the areas close to the epicenter,”; said Stuart Weinstein, deputy director of the Ewa Beach facility.

The center's alert was much quicker than the hours it took to issue warnings about the 2004 tsunami, due mainly to the increase of deep-water sensors from seven to 43, Maj. Gen. Robert Lee, head of Hawaii's National Guard, told PBS's NewsHour.

However, only a few of the sensors are in the Southwest Pacific region, according to a warning center geophysicist, adding to the time necessary for adequate information to be gathered and dispersed.

“;American Samoa is a small island, and most of the residents are around the coastline,”; said Filipo Ilaoa, deputy director of American Samoa's Honolulu office. “;There was no warning or anything at all. By the time the alert was out of the Pacific Tsunami Warning Center, it had already hit.”;

That is not to say that the damage had been done after the alert was sounded. Togiola T.A. Tulafono, the U.S. territory's governor, told a news conference that the worst destruction had been caused by the second and third waves in a series of four.

The Pacific Tsunami Warning Center has improved its operation in the past five years, and more attention is needed for communities to pass on warnings to residents and visitors.

Sirens were reported to have sounded in the Samoan capital of Apia but not on the other side of the island, where much of the damage occurred.

Warnings and sirens are of no use if no one is listening.