When Ivan hits sometime before 7 a.m. EST tomorrow, its full force will be felt for about a 260-mile radius from the storm’s eye. For New Orleans, the nearby Lake Pontchartrain could overflow and the city – which has the topography of a soup bowl and is mostly 10 feet below sea level – could be completely submerged.

Situated between the Rhode Island-sized lake and the Mississippi River, New Orleans relies on a system of levees, canals and huge pumps to keep dry. The city was flooded in 7 feet of water in 1965 when it was hit by Hurricane Betsy, which killed 110 people.

Experts say Ivan could be worse, sending water pouring over the levees and turning the streets into a toxic mixing bowl of raw sewage, gas and chemicals from nearby refineries.

The city’s Louis Armstrong Airport was ordered shut down September 14th. City officials state they have up to 10,000 body bags ready for Ivan, and up to 100,000 residents who rely on public transportation may not have the opportunity to evacuate.

The House of Blues is located in the French Quarter district of New Orleans, which is on the southern side of the city and near the banks of the Mississippi river. Tipitina’s Uptown is farther north, closer to Lake Pontchartrain.

Concert cancellations and postponements within the storm area are a certainty, and Pollstar has dropped all scheduled shows from New Orleans to Panama City, Fla., from today through Friday. Those include dates by Alan Jackson / Martina McBride, Peter Frampton and Tim McGraw’s Swampstock in Rayville, La., which was to take place September 19th.