coast. isaac, to get more strength before blowing ashore this evening. brandi hitt is there as the levees are put to the test. good morning, brandi. reporter: good morning, ula. that s the big concern. but officials say they do believe the levees will hold up in the storm. right now, there isn t a lot happening as you can see. the winds are slowly picking up. but that s about to change as isaac comes ashore. the gulf coast is bracing for isaac. it brings great danger with it from floodwaters. reporter: the storm is gaining strength as it moves across the gulf and is heading straight for louisiana. everybody leaves. nobody is staying. reporter: families in the lower ninth ward are boarding up their homes and moving out with the potential for flooding. the rain, potentially 18 inches of rain. reporter: a state of emergency has been declared in four states, with 5,000 national guard troops on standby. we re opening shelters in the morn panhandle of the state.