An earthquake shook buildings and startled Honolulu and Molokai residents shortly after 8 p.m. last night, but did not cause any damage. The magnitude 3.6 event was centered offshore, 30 miles northeast of Kailua, according to readings from the Hawaii Volcano Observatory. Although relatively weak, the quake prompted some high-rise residents in Makiki and Waikiki to leave their buildings, and scientists received reports from as far away as Waialua and Kapolei. Stuart Weinstein of the Pacific Tsunami Warning Center told KGMB that the quake was far too weak to generate a tsunami, but it was certainly strong enough to rattle some people. A resident intereviewed by the station compared the sensation to a bomb blast, and another said he feared his building would collapse. The islands were shaken by a magnitude 4.5 quake off the coast of the Big Island only a month ago. As in that quake, KHNL reported, the cause was likely the settling of the Earth's crust under the weight of the Hawaiian Islands.