Deadly floodwaters are still on the rise in Houston, which has been under a flash-flood emergency since Saturday night. Hurricane Harvey has been downgraded to a tropical storm, but is expected to bring more rain and heavy thunderstorms to the area through Wednesday. At least five people have been killed and more than 1,000 people rescued as record rainfall saturated Houston, the National Weather Service said. More than 20 inches of rain have fallen and 40 mph winds were blowing. Flood threats are spreading east to Louisiana. Houston Mayor Sylvester Turner said residents should remain vigilant through the coming days. Emergency task forces from cities across the country, including New York, Orlando, and Los Angeles, are heading to Texas to assist with the damage, NBC News reported.