A girl wades towards her flooded home the day after the passing of Tropical Storm Laura in Port-au-Prince, Haiti, Monday, Aug. 24, 2020. Laura battered the Dominican Republic and Haiti on it's way to the U.S. Gulf Coast, where forecaster fear it could become a major hurricane. (AP Photo/Dieu Nalio Chery)

As Tropical Storm Marco made landfall, the Gulf Coast turned its attention Monday to Laura, another system following just behind that could grow into a supercharged Category 3 hurricane with winds topping 110 mph (177 kph) and a storm surge that could swamp entire towns.

Still a for now, Laura, which is forecast to become a hurricane on Tuesday, churned just south of Cuba after killing at least 11 people in the Dominican Republic and Haiti, where it knocked out power and caused flooding in the two nations that share the island of Hispaniola. The deaths reportedly included a 10-year-old girl whose home was hit by a tree and a mother and young son who were crushed by a collapsing wall.

Laura was located about 81 miles (128 km) northeast of the western tip of Cuba and 765 miles (1,231 km) southeast of Lake Charles, Louisiana. The storm was moving west northwest at 20 mph (32 kmh) with maximum sustained of 65 mph (104 kmh).

The center of Laura will move away from Cuba and over the southeastern Gulf of Mexico overnight. The storm is then forecast to move over the central and northwestern Gulf of Mexico Tuesday night and Wednesday, and approach the northwestern coast of the Gulf of Mexico Wednesday night.

"Our sights are on Laura now," Gov. John Bel Edwards told a news briefing. "It has the potential to be a ."

Workers for the Southeast Louisiana Flood Protection Authority - West close floodgates in Harvey, La., just outside New Orleans, Monday, Aug. 24, 2020, in advance of Tropical Storm Marco, expected to come near the Southern Louisiana coast. (AP Photo/Gerald Herbert)

Shrimp trawlers and fishing boats were tied up in a Louisiana harbor ahead of the storms. Red flags warned swimmers away from the pounding surf. Both in-person classes and virtual school sessions were canceled in some districts.

In Port Arthur Texas, Mayor Thurman Bartie warned that unless the forecast changes and pushes Laura's landfall farther east, he will ask the city's more than 54,000 residents to evacuate starting at 6 a.m. Tuesday.

"If you decide to stay, you're staying on your own," Bartie said.

Officials in Houston asked residents to prepare supplies in case they lose power for a few days or need to evacuate homes along the coast.

Across the border in Louisiana's Cameron Parish, residents were preparing as well. Mandatory evacuation orders were issued for much of the parish, where officials said seawater pushed inland by the storm could submerge small coastal communities. In other coastal areas residents moved possessions to higher ground, filled sandbags and in one case, moved pews and other items from a church that has flooded before.

Cesar Reyes, right, carries a sheet of plywood to cut to size as he and Robert Aparicio, left, and Manuel Sepulveda, not pictured, install window coverings at Strand Brass and Christmas on the Strand, 2115 Strand St., in Galveston on Monday, Aug. 24, 2020. Ginger Herter, who manages the shop, was erring on the side of caution boarding up the storefront as she waits to see what path Tropical Storm Laura will take as it heads toward the Texas and Louisiana coasts. "I'd rather do this and have to take them down rather than scramble to get them up later in the week," she said. ( Jennifer Reynolds/The Galveston County Daily News via AP)

"Right now we're right in the bullseye but that could change," said Jeff Benoit, owner of B&O Kitchen and Grocery, a restaurant and Cajun food store in the southwest Louisiana city of Lake Charles. He was busy Monday, keeping track of what local officials were saying and preparing to shut the small business down if need be.

"It's just a matter of putting up some meats, making sure that's secure, best I can, anyway, and get the heck out of here," Benoit said.

State emergencies were declared in Louisiana and Mississippi, and shelters were being opened with cots set farther apart, among other measures designed to curb coronavirus infections.

Edwards encouraged evacuees to stay with relatives or in hotels. But officials said they made virus-related preparations at state shelters in case they are needed.

A lifeguard keeps his eye on surfers and swimmers in waves churned up by Tropical Storm Laura, Monday, Aug. 24, 2020, in Miami Beach, Fla. Tropical Storm Marco began falling apart Monday, easing one threat to the Gulf Coast but setting the stage for the arrival of Laura as a potentially supercharged Category 3 hurricane. (AP Photo/Wilfredo Lee)

As Marco was on its deathbed, the National Hurricane Center issued its first storm watches for Laura.

Forecasters posted a hurricane watch from Port Bolivar, Texas, to Morgan City, Louisiana, a tropical storm watch from Port Bolivar to San Luis Pass, Texas, and from Morgan City to the mouth of the Mississippi, where a collapsing Marco made landfall around 6 p.m. local time.

Heavy rain was expected across portions of the north-central Gulf Coast overnight, according to the National Hurricane Center. In Pensacola, Marco produced a one-day record rainfall of 2.22 inches, breaking a record set in 1961. But forecasters predicted Marco would no longer be a tropical storm by the end of the night.

More workers were being evacuated from production platforms in the Gulf of Mexico in anticipation of Laura's arrival, reducing offshore oil and gas production to less than one-fifth the normal activity. The Interior Department said Monday that 281 platforms had been evacuated by around midday. That's nearly half of those normally with workers on site.

As GOHSEP Director Jim Waskom, left, watches, and Dr. Daniel Burch does sign interpretation, center, Gov. John Bel Edwards answers questions while holding a media briefing about the state's activity related to Hurricanes Marco and Laura, in addition to hosting a Unified Command Group meeting afterwards. Both storms are forecast to impact Louisiana this week within a few days of each other Monday August 24, 2020, in Baton Rouge, La. (Bill Feig/The Advocate via AP) (Bill Feig./The Advocate via AP)

The department estimated that 82% of oil production and 57% of natural gas production in the Gulf has been shut down.

Much of the region was also put under a storm surge watch. Forecasters warned of as high as 11 feet in western Louisiana. Add to that 4 to 10 inches of rain expected when Laura arrives starting late Wednesday.

Once Laura moves into the toasty waters of the Gulf of Mexico that serve as fuel for storms, forecasters predict it will rapidly strengthen to hurricane status ahead of an expected Wednesday landfall. The question is just how much.

"I would still give it a pretty decent chance of a Category 3 or 4, not necessarily at landfall, at least during its lifetime in the Gulf," University of Miami hurricane researcher Brian McNoldy said. Many, but not all, storms in that area weaken just before landfall because of a late influx of dry air, he said.

  • Joe Marshall of the Southeast Louisiana Flood Protection Authority - West secures a floodgate they just closed in Harvey, La., just outside New Orleans, Monday, Aug. 24, 2020, in advance of Tropical Storm Marco, expected to come near the Southern Louisiana coast. (AP Photo/Gerald Herbert)

  • Lafaille Katia 28, removes salvage items from her flooded house the day after the passing of Tropical Storm Laura in Port-au-Prince, Haiti, Monday, Aug. 24, 2020. Forecasters fear Laura could become a major hurricane along the U.S. Gulf Coast. (AP Photo/Dieu Nalio Chery)

  • Yoleine Toussaint 22, removes mud from plates in front of her flooded house, one day after the passing of Tropical Storm Laura, in Port-au-Prince, Haiti, Monday, Aug. 24, 2020. Forecasters fear Laura could become a major hurricane along the U.S. Gulf Coast. (AP Photo/Dieu Nalio Chery)

  • Neighbors help Lafaille Katia, left, pick up a mattress at her flooded house the day after the passing of Tropical Storm Laura in Port-au-Prince, Haiti, Monday, Aug. 24, 2020. Forecasters fear Laura could become a major hurricane along the U.S. Gulf Coast. (AP Photo/Dieu Nalio Chery)

  • Residents fill sand bags on Courthouse Road in Gulfport, Miss., on Sunday, Aug. 23, 2020, as coastal residents prepared for impact of two possible back-to-back hurricanes. (Donn Hupp/The Sun Herald via AP)

  • Workers for the Southeast Louisiana Flood Protection Authority - West close floodgates in Harvey, La., just outside New Orleans, Monday, Aug. 24, 2020, in advance of Tropical Storm Marco, expected to come near the Southern Louisiana coast. (AP Photo/Gerald Herbert)

  • John Matherne, 62, hauled giant bags of sand to areas around Lafitte, La., as residents prepare for the arrival of two tropical storms along the south Louisiana coast on Monday, Aug. 24, 2020 . (Chris Granger/The Times-Picayune/The New Orleans Advocate via AP)

  • Workers for the Southeast Louisiana Flood Protection Authority - West close floodgates in Harvey, La., just outside New Orleans, Monday, Aug. 24, 2020, in advance of Tropical Storm Marco, expected to come near the Southern Louisiana coast. (AP Photo/Gerald Herbert)

  • Jerry Parria uses steel cable and metal anchors to tie down four tombs belonging to his grandparents and uncles in a small cemetery near Lafitte, La., as residents along the Louisiana coast prepare for two tropical storms, Monday, Aug. 24, 2020. Parria said the tombs floated away during a previous hurricane. (Chris Granger/The Times-Picayune/The New Orleans Advocate via AP)

  • Workers for the Southeast Louisiana Flood Protection Authority - West, close floodgates in Harvey, La., just outside New Orleans, Monday, Aug. 24, 2020, in advance of Tropical Storm Marco, expected to come near the Southern Louisiana coast. (AP Photo/Gerald Herbert)

  • Fisher High School students rest in the back of a truck after they helped place sandbags around the Lafitte, La., area as residents prepare for the arrival of two tropical storms along the south Louisiana coast on Monday, Aug. 24, 2020 . (Chris Granger/The Times-Picayune/The New Orleans Advocate via AP)

  • Houston Firefighter Paul Kessler prepares water-rescue equipment Monday, Aug. 24, 2020, at HFD Station 11 in Houston. Tropical weather systems are expected to hit Texas and Louisiana later in the week. (Jon Shapley/Houston Chronicle via AP)

  • Curious residents of Key West, Fla., flock to the Edward B. Knight Pier Monday, Aug. 24, 2020, to witness the wind and wave action of Hurricane Laura as the storm passes well to the west of the Florida Keys. (Rob O'Neal/The Key West Citizen via AP)

  • Carlos Joya, left, and Antonio Gomez board up the windows for a resident on 17th Street in Galveston on Monday, Aug. 24, 2020. As Tropical Storm Laura heads into the Gulf of Mexico, residents in Galveston began boarding up and preparing for the storm. ( Jennifer Reynolds/The Galveston County Daily News via AP)

The punch from back-to-back storms comes just days before the Aug. 29 anniversary of Hurricane Katrina, which breached the levees in New Orleans, flattened much of the Mississippi coast and killed as many as 1,800 people in 2005. Then a little less than a month later came Hurricane Rita which struck southwest Louisiana on Sept. 24 as a Category 3 .

On the Louisiana coast at Holly Beach in an area nicknamed the "Cajun Riviera," Eric Monceaux was frantically packing what he could take with him. Hit first by Hurricane Rita in 2005 and again by Ike in 2008, he does not plan to come back if Laura does its worst.

"That would be strike three," he said. "I'm 62, and I gave it two strikes. The third one is 'strike three, you're out' like a baseball game."