Hundreds of climbers are attempting to scale Mount Everest , the world’s highest peak, despite an unstable ice block dangerously hanging over the key trail, high travel costs and increased permit fees Around 492 climbers and an equal number of Nepali climbing guides are gearing up for the ascent to the nearly 8,850-meter (around 29,000-foot) high peak this month during the much anticipated window of good weather on the mountain. Climbers began gathering in April at the base camp, which is at an altitude of 5,300 meters (17,340 feet.) But for more than two weeks a massive and unstable block of ice, or serac, stalled them from moving further up the peak. The serac is part of the Khumbu Icefall, a constantly shifting glacier with deep crevasses and huge pieces of overhanging ice that can be as big as a 10-story building. The section is considered one of the most difficult and trickiest to climb.…