In a large mixing bowl, combine the egg, crumbs, onion, Worcestershire sauce, garlic powder, salt, and pepper. Add beef; mix well. Shape meat mixture into four 3/4-inch-thick patties.
Place the shaped patties on the rack of an uncovered grill directly over medium coals. Grill the burgers, uncovered, for 14 to 18 minutes or until done and the juices run clear, turning once halfway through the grilling time. Serve grilled patties on toasted hamburger buns. Makes 4 servings.
To test the temperature of the preheated coals, place your hand above the coals at the height the food will be cooked. Start counting and if you need to remove your hand after 4 seconds, the coals are medium.