The hillside in the city's southwest area gave way near dawn, but the homeowner was able to get out before his house slid down the 45-degree slope, The (Portland) Oregonian reported.
The house struck two other homes at the bottom of the hill, knocking one off its foundation and causing significant damage to another, the newspaper said.
Emergency crews evacuated the area and shut down all utilities as a precaution.
The cause of the landslide was not immediately known.
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