A state of emergency has been declared for Samoa, the Australian Broadcasting Corp. reported.
The Category 2 storm, with winds of up to 68 mph, destroyed homes and crops, flooded rivers, toppled trees and power lines, flooded roads, damaged buildings and forced the airport to close, officials said.
Storm and flood warnings were posted and forecasters said Evan will cause a sea surge of nearly 10 feet, the Australian broadcaster said.
Evan was expected to make landfall in neighboring American Samoa Thursday night.
Neville Koop, meteorology and climate adviser to the Secretariat of the Pacific Regional Environment Program, told Radio Australia Evan was expected to track south toward the island nation of Fiji.