Flooding coastal roads and knocking out power to 500,000 homes and businesses, Hurricane Isaac pelted New Orleans and other parts of the Gulf Coast with high winds and soaking rains on Wednesday, seven years to the day after Hurricane Katrina devastated the region. The first reports on Isaac's impact were frightening for those with memories of Katrina still raw in their heads, but, as of midday Wednesday, the damage has been limited. Here, a brief guide:

Is New Orleans facing another Katrina?
No, says New Orleans Mayor Mitch Landrieu. The city "dodged a bullet" this time. Isaac hit with 80 mile-per-hour winds — far weaker than Katrina, which killed 1,800 people when it slammed into the Gulf Coast with sustained winds of 125 miles per hour, and a record storm surge that exceeded 20 feet in some places. Isaac's surge, forecasters said, was probably in the six- to 12-foot range along the Louisiana and Mississippi coasts — still enough to do harm. "It's not too bad, says Chipper McDermott, mayor of Pass Christian, Miss., which was wiped out by Katrina, "but the whole coast is going to be a mess."

Is there still danger of flooding?
Yes. A 12-foot surge of seawater rushed over the top of an 8-foot-high levee in Plaquemines Parish, La. The churning waters trapped some families in their homes. Isaac "delivered more of a punch than originally thought," says Billy Nungesser, president of Plaquemines Parish. "We have reports of people on their roofs, in attics, in 12 to 14 feet of water." Nungesser's own home sustained "more damage than it did during Katrina." Luckily, Plaquemines Parish is a sparsely populated rural community, so relatively few people and buildings are at risk.

What about New Orleans?
The much more densely populated city has beefier defenses than Plaquemines. New Orleans is particularly vulnerable to flooding since much of it sits below sea level, but it's protected by a $14.5 billion network of levees, flood walls, and pumps that the Army Corps of engineers installed to replace the defenses that failed so catastrophically in 2005. Some barriers are as high as 26 feet. Those levees and flood walls, facing their first test, are expected to hold, although flooding is still a threat.

Are we out of the woods yet?
Not quite. This massive storm is moving inland at only six miles per hour, an excruciatingly slow pace. That means Hurricane Isaac could take 30 hours or more to slog across some areas, drenching them in 20 inches of rain. "We're just kind of waiting for the storm to go through," says Philip Allison, a spokesman for local power company Entergy New Orleans. "Once the storm passes, we'll start assessing damage and try to get some lights back on wherever we can."

Sources: Associated Press, CNN, New Orleans Times-Picayune, New York Times, NPRWall Street Journal, Washington Post