NOSARA, Costa Rica - (AP) - A powerful, magnitude-7.6 earthquake shook Costa Rica and a wide swath of Central America on Wednesday, collapsing some houses, blocking highways and causing panic, but officials said there was only one reported death, from a heart attack. The USGS said the 8:42 a.m. (10:42 a.m. EDT; 1442 GMT) quake struck about 38 miles (60 kilometers) from the town of Liberia. The magnitude initially was estimated at 7.9. In the town of Hojancha a few miles (kilometers) from the epicenter, city official Kenia Campos said the quake knocked down some houses and landslides blocked several roads. One man died of a heart attack caused by fright, said Carlos Miranda, a Red Cross worker in the city of Liberia. A preliminary review revealed some structural damage near the epicenter, but no reports of direct deaths or injuries caused by the quake, said Douglas Salgado, a geographer with Costa Rica's National Commission of Risk Prevention and Emergency Attention. He said a tsunami alert had been called off for Costa Rica. Wednesday's quake occurred in a seismically active zone where the Pacific tectonic plate is diving beneath Central America. The quake was fairly deep - 25 miles (41 kilometers) below the surface. Deeper events tend to be less damaging than ones closer to the surface, but more widely felt. The last deadly quake to strike Costa Rica was in 2009, when 40 died in a magnitude-6.1 temblor. The last similar-sized quake to hit the country was in 1991 when 47 people were killed in the Limon-Pandora area.