ANCHORAGE, Alaska (AP) — Back-to-back earthquakes measuring 7.0 and 5.7 shattered highways and rocked buildings Friday in Anchorage and the surrounding area, sending people running into the streets and briefly triggering a tsunami warning for islands and coastal areas south of the city. No tsunami arrived and there were no immediate reports of deaths or serious injuries. The U.S. Geological Survey said the first and more powerful quake was centered about 7 miles (12 kilometers) north of Anchorage, Alaska’s largest city, with a population of about 300,000. People ran from their offices or took cover under desks. The 5.7 aftershock arrived within minutes, followed by a series of smaller quakes.