ATHENS, Greece—A strong, prolonged earthquake with a preliminary magnitude of at least 5.8 struck the Greek island of Crete on Monday, killing one person and injuring 20, while damaging homes and churches and causing rock slides near the country’s fourth-largest city. The quake sent people fleeing into the streets in the city of Heraklion, and schools were evacuated. Repeated aftershocks—described by witnesses as feeling like small explosions—rattled the area, adding to damage in villages near the epicenter. “The earthquake was strong and was long in duration,” Heraklion mayor Vassilis Lambrinos told private Antenna television. The Athens Geodynamic Institute, which gave the 5.8 magnitude, said the quake struck at 9:17 a.m. (0617 GMT), with an epicenter 246 kilometers (153 miles) south southeast of the Greek capital, Athens. Hospital officials said 20 people had been treated for injuries, ten of them receiving first aid. International and domestic flights to Heraklion airport weren’t …