Hurricane Isaac nears landfall

Matthew Pettus holds a sheet open in the wind on the levee near Lake Pontchatrain as Hurricane Isaac approaches in New Orleans, Aug. 28, 2012.

Miguel Llanos, NBC News  — Hurricane Isaac continued building strength on Tuesday, closing in on New Orleans and the entire Louisiana coast as a slow-moving giant expected to make landfall shortly and then dump up to 20 inches of rain in some spots over two days. Even before landfall, some flooded roads and power outages were reported in Louisiana and Mississippi.

A group of men await Hurricane Isaac in New Orleans, Aug. 28.

Joshua Keegan, 10, left, and Ruffin Henry, 10, play with Scout in a flooded area outside of the levee system along the shores of Lake Pontchartrain as Hurricane Isaac approaches New Orleans, Aug. 28.

Andrew Sessoms sit on a park bench at a flooded beach as Hurricane Isaac approaches the Gulf Coast in Waveland, Miss., Aug. 28.