A downed tree near the U.S. Capitol. People all across the mid-Atlantic are still without power as temperatures rise into the low 100s. Reuters

The power outages across the eastern United States caused by Friday's violent storms may not be fixed until the end of the week, reports say. The storm, in part caused by a brutal heat wave, has already killed at least 13 people and knocked out popular websites including Instagram, Netflix and Pinterest.

So far Virginia, West Virginia and Ohio have all declared states of emergency. With temperatures expected to break the upper 90s and low 100s in some areas, getting power back to the millions of people without air conditioning, working refridgerators, or power tools to clean up fallen trees is a top priority for officials.

As of Sunday, there were still more than 3 million people across the mid-Atlantic region and eastern Midewest without power.

Ohioans in affected areas should, if possible, stay tuned to their radios or TVs for the information on where they can go for assistance, Ohio Gov. John Kasich advised. Those without power can call their local 211 numbers for information on where to turn for help. Folks should also knock on their neighbors' doors to make sure they're ok and look out for those who they might know need some extra help. Together we'll get through this.

People without power all across the region have congregated in large community centers like shopping malls, movie theaters and other large spaces that have been able to keep their air conditioners turned up high thanks to powerful generators.

Others have taken to hotel rooms or travelled to be with friends and family. Emergency officials and politicians in every state have stressed the need for people to trust and work together. They also encourage people not to venture outside carelessly, citing downed power lines as well as unstable trees.

Out of the 13 killed, six were in Virginia, a state that was hit particularly hard. They included a 90-year-old woman asleep in her bed when a tree slammed into her home, and a man who was believed to have drowned after his boat capsized. Two cousins on a camping trip were also killed when a tree fell onto their tent.

Power crews are slowly making their way through the Washington, D.C., area, but in the meantime many libraries, senior centers, YMCAs and the like have provided refuge for displaced and sweaty residents. The Washington Post has a list of open locations across Viriginia, Maryland and the District of Columbia; it also reports that all Costco stores in the region have been able to stay open.

Almost 90,000 people woke up without power Sunday, looking at a day where the temperature was expected to rise past 100 degrees.

Myra Oppel, a spokeswoman for D.C. energy utility Pepco, reported there is are still more 400,000 outages in Washington and its suburbs. We do understand the hardship that this brings, especially with the heat as intense at is. We will be working around the clock until we get the last customer on.

The deputy secretary for Maryland's Department of Health and Mental Hygiene, Frances B. Phillips, has advised residents that one of the most important steps that's often overlooked is simply drinking water. In a situation where temperatures are high and air conditioning is not readily available dehydration is a major problem.

Federal emergency officials said the storms also caused damage in Ohio, Kentucky, Pennsylvania and West Virginia. The White House said President Barack Obama spoke with their governors to receive updates. Regions as far north as Atlantic City, N.J., reported power failures.