New rain started falling again Friday in mountain towns where mudslides and flooding killed at least 500 people, slowing rescuers' efforts to reach survivors. The known death toll rose slightly overnight in three towns in Rio de Janeiro state in one of Brazil's deadliest natural disasters on record. However, officials fear the death toll could rise sharply, as local reports say hundreds of people are missing. Swarms of rescuers were in the area 65 kilometers north of the city of Rio de Janeiro, but officials said the problem was getting them to remote areas isolated after roads were washed out. Despite the new rain, no more mudslides have been reported. Heavy rain unleashed the mudslides before dawn Wednesday, burying people as they slept. Many of the victims lived in flimsy homes on steep hillsides.