The shaded area will not have water service for several days.

Hundreds of thousands of residents of Prince George’s County will go without running water tonight when the local sewer authority shuts down a major pipe that needs emergency repairs.

The Washington Suburban Sanitation Commission said this morning that it needs immediately to replace multiple sections of a 54-inch pipe that serves the southern part of the county. Unfortunately for as many as 200,000 customers, there is no redundancy in the local sewer grid, and that when the pipe is shut down at 9 p.m., the affected area will have perhaps another 12 hours of running water. After that, it’ll take several days for crews to replace the damaged pipe and get things moving again.

Water restrictions begin tonight, with residents being advised to take short showers, flush toilets intermittently, stop watering lawns and gardens, cease running dishwashers and washing machines, and stock up on as much bottled water as possible.

Prince George’s Fire and Emergency Medical Services is filling several tanker trucks should any fires break out. The county government is also setting up an emergency operation center beginning at 11 p.m. tonight.

The problematic pipe is known as a pre-stressed concrete cylinder, built from a thin-seal core, layered in concrete, and surrounded by steel wires, which gives the line its strength. The pipe dates back to 1965, but a spokesman for WSSC told DCist earlier Tuesday that years of erosion has caused some of those wires to snap. Now, structural integrity is failing. Engineers will determine how many of the pipes 16- and 20-foot sections need repairing once the pipe is excavated.

But the loss of water services couldn’t come at a worse time for Prince George’s County. The D.C. region is in the middle of a week-long heat wave, with temperatures lingering above 90 degrees and stifling humidity making it feel hotter than 100 degrees outside. The county is opening its cooling centers.

The affected communities include Morningside, Hillcrest Heights, Camp Springs, Forest Heights, Temple Hills, and Oxon Hill, as well as Joint Base Andrews. In Oxon Hill, businesses at National Harbor are preparing to shut down, including the Gaylord National Resort, which is closing at noon Wednesday and refunding reservations through Saturday, when it expects to re-open.

For Prince George’s residents who just want to book it while the water is out, Kimpton Hotels, which owns 11 locations in the Washington area, is offering people 20 percent off normal room rates.

Meanwhile, Joint Base Andrews will reduce its operations to “mission-essential personnel” only beginning Tuesday evening. But by taking it slow for a few days, the Air Force facility’s commanding officer suggested a silver lining for D.C.

“If you live on Andrews, I think tomorrow would be a great day to get out and go see Washington, D.C.” Col. Bill Knight, the commander of the 11th Air Wing, said in a news release. “While this main break affects a lot of people in our area, there’s a lot of Washington, D.C. that is not affected and we encourage you to get out and go experience our nation’s capital.”

Restaurants throughout the affected are shutting down, with county health inspectors going door-to-door, Russ Ptacek, WUSA’s health czar, reports.

But some will have it much tougher than others, and not everyone is able to rush out to their nearest supermarket or convenience store to hoard water. To that end, Food and Friends, a D.C.-based food charity that delivers meals to the terminally ill and other homebound individuals, will be delivering 1,000 gallons of water to its roughly 100 Prince George’s clients tomorrow.

The busted pipe was installed in 1965. The WSSC will spend the next few days