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Threat of flooding from troubled Louisiana canal lock eases; remnants of Isaac push north

The Pearl River in Louisiana is rising and officials are debating whether to evacuate 5,000 homes. Meanwhile, the National Guard airlifted hay to cattle. NBC's Gabe Gutierrez reports.

Updated at4:36 p.m. ET: Engineers on Sunday were assessing the integrity of a lock along a canal north of New Orleans that threatened to fail and send water from the Hurricane Isaac-swollen Pearl River flooding through neighborhoods.

A flash-flood warning was in effect for east-central St. Tammany Parish, a community north of New Orleans in southeast Louisiana but officials said the threat of disaster had eased.

Parish President Pat Brister on Sunday changed the evacuation of the area between Bush and Hickory, east of Highway 41,  from mandatory to voluntary.  

"The Army Corps of Engineers Vicksburg District has lowered the pressure on Lock 2 near Bush. The Corps informed President Brister this morning that the threat level is lowered significantly," St. Tammany Parish officials said in a statement on their website.

Residents struggle with the aftermath of Hurricane Isaac, which has left behind feet of standing water. In Louisiana, about 2,500 people are still in shelters. NBC's Gabe Gutierrez reports.

"As there is still a potential threat, even though reduced, a voluntary evacuation remains in place until the Army Corps of Engineers deems the Lock stable and safe."

Saturday night, parish emergency officials said that the opening of valves had relieved pressure on Lock 2 on the Pearl River Diversion Canal but an evacuation order would remain in place.

Coastal Protection and Restoration Authority

Aerial view of threatened Louisiana lock

Water began pouring over the lock and leaching around its sides Saturday, prompting fears the entire structure could be washed away, sending a wall of water into nearby neighborhoods. 

Officials had said earlier Saturday that the failure of the lock appeared imminent. That promoted the mandatory evacuation of thousands of residents in some 1,200 homes.

Parish Sheriff Jack Strain Strain and Brister late Saturday said the threat of the lock failing had been lessened after crews managed to open valves to release some of the water and reduce pressure on the structure.

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"The lock has been stabilized somewhat,” Strain said, according to nola.com.

Handout / Reuters

St.Tammany officials inspect Lock 2 on Saturday.

"The worst-case scenario -- we don't believe that's going to happen,'' he added.

The National Weather Service is projecting the Pearl River, at the town of Pearl River, to crest early Monday morning at 19.5 feet. 

In Mississippi, U.S. Secretary of Homeland Security Janet Napolitano toured areas damaged by Isaac, one day before President Barack Obama was scheduled to see first-hand Isaac's destruction in Louisiana.

Napolitano was told about 1,600 or more homes were flooded by overflowing rivers and two people reportedly died in Mississippi. Most of the damage was in Pearl River and Jackson counties.

The secretary praised emergency officials and said Obama was calling her frequently for updates. "The president has been on top of it," she said, The Associated Press reported. "We are here, we have been here, we will remain here."

As residents in Louisiana, Mississippi and Arkansas began surveying the damage to their homes, remnants of Isaac pushed their way north, spinning off tornadoes in southeast Missouri and threatening flash-flooding in parts of Tennessee and Kentucky.

The Gulf Coast is struggling to recover from Hurricane Isaac as nearly 400,000 homes and businesses are without power. NBC's Gabe Gutierrez reports.

In Missouri's Bootheel region, Dunklin County sheriff's deputies tracked a tornado that destroyed a farm shop and damaged a home's roof, The Associated Press reported.

On Sunday morning nearly 265,000 customers in Louisiana, 13,000 in Mississippi and 7,300 in Arkansas remained without power, according to The Weather Channel.

Isaac was the first hurricane to strike the United States this year and it hit the New Orleans area almost exactly seven years after Hurricane Katrina devastated the city, causing an estimated 1,800 deaths. 

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