As Hurricane Isaac barreled its way toward the Gulf Coast on Tuesday, authorities were out in force warning residents to take necessary, life-saving precautions.
"Do not let this storm lull you into complacency. That would be a terrible mistake," said New Orleans Mayor Mitch Landrieu.
PHOTOS | New Orleans ahead of the storm http://bit.ly/U8BAAq
Although Isaac -- just barely a Category 1 hurricane -- doesn't pack the punch of Hurricane Katrina seven years ago, such storms can "kill you or hurt you very badly," he said, citing flying debris and the dangers of driving through standing water.
"You've heard the stories of 'there but for the grace of God go I,'" said Landrieu, "unfortunately too many times."
He called on residents to be vigilant.
President Barack Obama, speaking from Washington, said, "Now's not the time to tempt fate. Now's not the time to dismiss official warnings. You need to take this seriously."
The president signed an emergency declaration for the state of Mississippi on Tuesday, as he had for Louisiana on Monday.
As of Tuesday afternoon, Isaac's maximum sustained winds were at 75 miles per hour, just strong enough to give it hurricane status, as it churned northwest through the Gulf at about 10 miles per hour, the National Hurricane Center said.
Forecasters expect Isaac to gain strength before it makes landfall, which could be as early as Tuesday evening.
"Hurricane conditions are expected to reach the coast by late afternoon," and the storm's center "should reach the coastline of southeastern Louisiana as early as this evening," the hurricane center said.
Isaac's forward movement is expected to slow down, and if it slows enough that it makes landfall after midnight, it will strike on Katrina's seventh anniversary.
In New Orleans, the Army Corps of Engineers told CNN it was closing the gate to the West Closure Complex, one of the world's largest pump stations, capable of pumping storm water at 20,000 cubic feet per second.
As of 1 p.m. CT, Isaac's center was about 135 miles southeast of New Orleans, and about 55 miles south-southeast of the mouth of the Mississippi River, the hurricane center said.
Hurricane-force winds extended 60 miles, and tropical storm-force winds extended 185 miles, the center said.
Isaac's slow pace will give it time to wreak havoc in some areas.
Total rainfall could be 14 inches in many places, and isolated parts of southeast Louisiana, southern Mississippi, southern Alabama and the Florida panhandle could get as much as 20 inches, the hurricane center said.
"The combination of a storm surge and the tide will cause normally dry areas near the coast to be flooded," the hurricane center said.
The storm could spawn tornadoes along the northern Gulf Coast on Tuesday, forecasters said.
The U.S. Coast Guard said it was was searching for a "missing jet skier" off the coast of Pensacola, Florida. The man's wife reported him missing Monday night.
As Hurricane Isaac builds, "the increasing winds and seas make search conditions extremely difficult and unsafe for aircrews," Coast Guard spokesman Timothy Williams said. "As Isaac approaches, Coast Guard aircrews will temporarily suspend their search efforts until the storm passes and weather conditions become safe enough to resume the search."
In Biloxi, Mississippi, popular casinos began to close down Tuesday.
The hurricane center called on people at ports, docks and marinas to "urgently complete" emergency preparations. For people who live on boats, it was time to "make final preparations for securing your craft before leaving it."
In New Orleans, Landrieu said officials "have a plan in place to secure the city, and we have a plan to respond quickly in the event of emergencies. We're confident that the work we've done in the last few years makes us fully capable of handling this type of storm."
By Tuesday morning, it was too late to evacuate New Orleans, Landrieu said.
Several New Orleans residents told CNN they planned to wait out the storm and were not concerned that the nightmare of Hurricane Katrina in 2005 would be repeated. Isaac is not predicted to bring such dire conditions, and law and order have improved vastly, they said.
Jackie Grosch had to rebuild her home in Louisiana after Hurricane Katrina, but the St. Bernard Parish resident said she was going to wait Isaac out.
"Well, it gets old after a while -- packing up, taking the journey to wherever we're going to go. We thought about it and decided to stay," she said.
Nonetheless, her family is prepared with a generator, weather radio and life jackets -- "just in case."
A levee system fortified after Katrina will keep her home safe, she said.
"I don't know if it's going to be a true test, because they're saying it's not going to be that bad. But you never know what bad is. We didn't think Katrina was going to be bad, either."
Katrina made landfall as a Category 3 hurricane with 125-mph winds
Most of Katrina's nearly 1,800 deaths occurred when the protective levees around