More than a third of the island’s residents live either in the city of Kailua-Kona to the west of the volcano, or about 23,000 people, and Hilo to the east, with about 45,000. Officials were most worried about several subdivisions some 30 miles (50 kilometers) to the volcano’s south that are home to about 5,000 people.
Article source: https://www.huffpost.com/entry/hawaii-volcano-residents-warned_n_63856c45e4b006c42d41a221