time zone. we begin with a wave of fear. in the midst of the worst flooding seen in some parts for a generation, rising waters along the bloated mississippi river are continuing to push downstream forcing difficult decisions in louisiana. nbc s jay gray reports. reporter: a frantic rush to stay ahead of the floodwaters continues in yazoo city, mississippi. can t be sure of anything. reporter: the house is losing right now in tunikca. the city s nine casinos have been swallowed by water. this is a flood of a generation. nobody has seen water this high, and it it likely nobody ever will again. this is a monumental flood. reporter: downriver in louisiana, crews along interstate 10 rush to finish a temporary levee. bracing for the possibility that the army corps of engineers will open the spillway diverting the mississippi over 3 million acres in southwestern louisiana putting 13,000 structures and 25,000 people in jeopardy. i say huge and immense. it s hard to descri