A small plane clipped a downtown Anchorage office building and then slammed into a nearby commercial building Tuesday, killing at least one person onboard, authorities said. Anchorage Assistant Fire Chief Alex Boyd said there were no injuries on the ground, but it's unclear if anyone else was in the plane. The plane clipped the corner of the office building, where some state employees work, at about 6:20 a.m. It then crashed into the lower side of an adjacent multi-story commercial building, setting it on fire. ent Haina, a 747 captain for UPS, said he was taking out his garbage when he saw the plane go down at a shallow angle and disappear behind a building. He then heard a loud thud and saw a plume of black smoke. Haina said the wind was howling at the time. "(The engine) didn't sound like it was in trouble, but the weather was pretty windy," he said. "I said to myself it's not good weather to be flying in." Immediately after the crash, the power went out in Haina's condo, he said. Crews responded quickly and had the blaze under control, said Don Tallman of the Anchorage Fire Department. The commercial building appeared to be unoccupied at the time of the crash, though crews were searching it to make sure, Tallman said. Authorities cordoned off an area around the building, closing several roads. The aircraft also struck a transformer, Boyd said, and some power outages were reported in the area. The crash happened in the heart of downtown, in an area surrounded by office buildings, hotels and other businesses less than 10 miles from the Anchorage airport. It occurred before most nearby businesses opened for the day. Federal Aviation Administration spokesman Ian Gregor said both the FAA and the National Transportation Safety Board will investigate. He had no additional details on the plane or the crash.