The well established tsunami warning system apparently triggered as it was supposed to but the earthquake was too close. The wave energy, created by the strong tremor, travels at several hundred kilometers an hour. Four huge waves reached the shore in minutes. Samoan villages sit right on the water with often only a paved road and a string of palm trees between fales and the sea, many people just could not get away in time.
On the two islands of Samoa, Savai'i and Upolu, 140 people have been convirmed dead, up to 15000 people have been made homeless and 50 villages along the south and south east coasts have been reduced to rubble.
Beach fales on the south coast of Samoa
The pier at Sinalei
(photo from stuff.co.nz)