Intense rains from Hurricane Alex shut down Mexico's richest city, Monterrey, as floods killed six people, swept away cars and swamped wealthy suburbs with mud and rocks. More than a year's worth of rain fell in three days from the first named Atlantic storm of the 2010 season. It swelled dry river beds and destroyed chunks of highway in the city, about 1,000 km north of Mexico City. The floods dragged away furniture from mansions in the San Pedro Garza Garcia suburb, Mexico's wealthiest municipality. <br/><br/>Many businesses in the city, which has the highest per capita income in Mexico, shut down as authorities closed bridges over the Santa Catarina river, usually bone-dry but surging yesterday. Thousands of homes were without water and electricity and many huddled in shelters. Although the rain lessened, authorities were still on high alert.<br/>