"This is a local levee. They knew it's prone to flooding. That's why it was under a mandatory evacuation order. About 20 people or so didn't leave," said Col. Mike Edmonson, superintendent of Louisiana State Police.
"We're going to get out there to them. We're going to do everything we can to get them out of there. But we're not going to put further people in harm's way," Edmonson said.
With the storm expected to be moving across the state for hours, if not days, he said, "This is something we're going to be in for the long haul. This is not anywhere anytime soon."
Isaac bounced off the mouth of the Mississippi River Tuesday night, making its first landfall. It then moved onto Grand Isle, a barrier island in Jefferson Parish, where it stalled for several hours.
Jesse Delcambre, who stayed in the town hall because her fiance is a town employee, said the island was still covered by about 2 feet of water on Wednesday morning.
"The houses over here are all 12, 14 feet above ground on pilings," she said. The few on slabs are flooded, she added.
Jefferson Parish President John Young said the island may have been covered by up to 5 feet of water during the storm.
"I've been out and about since 3 o'clock this morning. The pump operators are keeping up, the pump stations are keeping up and working properly, so there's not a lot of street flooding," he said.
Any flooding reported was all in low-lying areas prone to flooding, he said.
"The 30 to 40 people who stayed there are accounted for and safe," he said.