(USA TODAY) -- Here are several things you can do, if you're in the Boston area or farther away, to help those affected by this tragedy.

1. The Salvation Army is providing support to survivors and first responders. You can donate-clothes, food, books, gift cards, etc.-here.

2. Donate blood. This is always crucial when disaster strikes. Visit the American Red Cross website and learn how to help. Or call 1-800-RED-CROSS (733-2767).

3. Some marathon runners are stranded in Boston and need a place to stay. If you live in the area or are close to it and are willing to pick up people and open up your home, click here to find out how you can offer housing.

4. For families trying to locate loved ones, call the Boston Mayor's hotline at 617-635-4500. And if you have any tips to help out with the investigation, call 1-800-494-TIPS (8477), text the word TIP to CRIME (27463), or call 1-800-CALL-FBI (225-5324) and choose prompt #3.

5. If you're concerned about a runner in the marathon, you can see his or her last check in on the Boston Marathon site. You can also track down a loved one via Google's Person Finder if you're worried they were near the blasts.