Coastal residents in low-lying areas of Louisiana and Cuba were evacuating on Sunday, while roads turned to rivers in Haiti's capital city, as twin hurricanes threatened the Caribbean and US Gulf Coast.
Marco, which strengthened to a hurricane on Sunday and is forecast to hit the Louisiana coast on Monday, will be followed by Tropical Storm Laura, now over the Dominican Republic and expected to travel across Hispaniola and Cuba and strengthen to a hurricane before striking the Gulf Coast on Thursday.
In Port-au-Prince, Haiti, videos on social media showed people wading waist-deep in muddy water in some of the worst flooding the capital has seen in years. Haiti is especially vulnerable to intense rains due to shoddy infrastructure and deforestation which increases the likelihood of landslides.
Authorities called on residents along the Artibonite River to evacuate due to risks the Peligre Hydroelectric Dam might burst its banks.
Haiti was the first to report a death from Laura, where a 10-year-old girl was killed when a tree fell on her home in the southern town of Ans-a-Pitres.
With hopes dashed that the mountains of Hispanola would weaken the storm, Cuba scrambled on Sunday to prepare for Laura.
Evacuations were underway in eastern parts of the Caribbean's largest island, where the storm was expected to strike Sunday evening, bringing flooding, before traveling along the entire island on Monday.
Back-to-back hurricanes arriving at the US coast within days "could result in a prolonged period of hazardous weather," National Hurricane Center forecaster Stacy Stewart warned on Sunday.
The Federal Emergency Management Agency has sent incident management teams to emergency operations centers in state capitals in Louisiana and Texas, said spokesman Earl Armstrong. The agency is prepared to handle back-to-back storms, he said, pointing to 2004 when four hurricanes took aim at Florida in a six-week period.
Officials in Louisiana's coastal Lafourche Parish ordered a mandatory evacuation for residents of low-lying areas at noon on Sunday. The US Coast Guard also raised its warning for the Port of New Orleans, calling for ships to make plans to evacuate some areas.
The potential for flooding and evacuations added to worries about the spread of Covid-19. Tulane University, the largest private employer in New Orleans, said it will close its testing center on Monday due to potential flooding and power outages and called on students to maintain social distancing guidelines.
In Grand Isle, at the state's southern tip, authorities were placing sandbags to bolster its protective levy while energy companies continued to pull workers from offshore platforms and shut production in the US Gulf of Mexico wells.
Laura could strengthen and become a Category 2 or 3 hurricane and move west, closer to the Houston-Galveston area, bringing flooding rains late Wednesday or Thursday, said Chris Kerr, a meteorologist and director of offshore forecasting for DTN, an energy, agriculture and weather data provider.
Refining company Equinor has finished evacuating its Titan oil-production platform in the US Gulf of Mexico and shut-in oil production at the facility, a spokesman said on Sunday.
Oil producers including BP, Chevron and Royal Dutch Shell had shut 13 per cent of the region's offshore oil production on Saturday. The region accounts for 17 percent of total US oil production and 5 percent of US natural gas output.