Thousands of Louisianans broke out sandbags or fled to higher ground Thursday as Tropical Storm Barry threatened to turn into the first hurricane of the season and blow ashore with torrential rains that could pose a severe test of New Orleans' improved post-Katrina flood defenses . National Guard troops and rescue crews in high-water vehicles took up positions around the state as Louisiana braced for the arrival of the storm Friday night or early Saturday. President Donald Trump on Thursday night declared a federal declaration of emergency for Louisiana, authorizing the Department of Homeland Security and Federal Emergency Management Agency to coordinate all disaster relief efforts.