The names of the two people have not been released, but KITV-TV reports a husband and his wife were in the room that was hit. The 50-year-old man suffered a fractured leg, while his 36-year-old wife was trapped under the debris.
Honolulu Fire Department Capt. Gary Lum described the two as "very lucky."
The station reports the couple's 10-year-old son was home at the time, but was not hurt.
The home is in a subdivision built below a hillside. Geologists and soil engineers were called to assess the area.