What allowed that land bridge over what is now the Bering strait to form?

According to the most accepted theory, the glaciation, or drastic drop of temperatures in the northern hemisphere of the planet spreading ice and snow well below the Arctic Circle, causes the sea level of all the oceans in the world to fall some 60 feet around all the coastlines, including the area of the Bering Strait. Furthermore, it is believed that the remaining body of water currently passing between the Arctic Circle and the Pacific Ocean froze up forming a thick layer of ice, which allowed the transit of both humans and animals between the American and Asian continents.