The scarcity of Port-a-go to the bathroom. Areas of cellular interference. Ambulances caught in congestion. These are the conditions for which emergency managers across the country are waiting for the week of August 21.

No, we do not expect a big hurricane. This is not a preparation for a cyber attack after someone turned the FBI. Beyonce has a national tour, but the cause is a star of a different type.

The solar eclipse comes – the first in 99 years touring the continental United States – so many fans that disaster preparations are in place, due to the large number of travelers expected to try to get the first few points screen.

It is expected that approximately 7.4 million people will gather in a group of 70 miles across the United States to see the shadow of the moon blocking the sun for a two-minute window on August 21, according to solar eclipse education site.

The entire path, the area where the sun is completely blocked, stretching from Oregon to South Carolina.

Here is why many people expect a disaster: Oregon has a population of 4 million people, and is expected to eclipse to attract 1 million visitors to the state for several days. In Missouri, the preparations are similar to those of a snowstorm or “all, the St. Patrick’s parade in a World Series celebration,” said Chris Hernandez, spokesman for the city of Kansas City, Missouri, one of the Major metropolitan areas of the eclipse path.

All of these visitors should block interstances and public and local roads, both days before and after the eclipse, such as fever during emergency evacuations, said Brad Kieserman, vice president of operations and logistical disaster at the American Red Cross. “Some of these places will never see traffic like this,” he said. In some areas, “the population will double or triple.”

Once visitors arrive, they will need bottled water, shelter and toilets. And, of course, the sunglasses.

In Colombia, in South Carolina, the city’s main museum has purchased 5,000 bottles of water for thirsty viewers and the city government plans to send trucks to frequently replace the water stations provided.

Wyoming Grand Teton National Park staff hired 200 more portable toilets to accommodate “their busiest day in history, that is, the past or future,” says Kathryn Brackenridge, Eclipse coordinator for the city of Jackson, Wyoming.

She was hired earlier this year to organize the details of emergency preparedness and marketing related to the eclipse.

Merritt McNeely, Director of Marketing at State Museum of South Carolina, a local company called portable toilets are six months to book their services. She is concerned about the national shortage of a portable bath.

National Building Rental, which rents portable toilets in the United States, has not seen an increase in demand, but “there will likely be last minute requests to date,” said Scott Barley, director of corporate sales and marketing.