What was supposed to be a joyful, carefree day on Monday in Boston-the Boston Marathon was taking place, it was Patriots Day, and many people had the day off from school and work-quickly changed after two bombs exploded at the finish line of the marathon, killing three and injuring more than 170 runners and spectators.

Two days later, the smoke may have cleared, but people are still looking for answers. It could be days, weeks, or months before we know exactly what happened and may be able to comprehend why it happened. Dealing with a tragedy of this magnitude can be difficult for anyone, even if you didn't personally know anyone involved. It's hard to know what to think, say, or do in these situations, and it can be even harder to talk about them with your children or family members.

We've compiled a list of resources that we've found to be helpful in times of crisis. Check them out below, and feel free to add your own in the comments below.

1. Donate. If you want to help victims from Monday's bombing in a tangible way, has set up a portal that allows you to donate money to the victims and their families through a range of charities.

2. Talk to someone. Whether or not you live in Boston, it's normal to feel shaken up by what happened, and it can be hard to explain the situation to your children. ABC News has rounded up some expert tips on how to approach the conversation with your kids, and Huffington Post Healthy Living has compiled advice on how to deal with potential post-traumatic stress disorder. If you were at the Boston Marathon or the surrounding area and are okay, or are uninjured but stuck without a ride out of the city, let your friends and family know by writing on the American Red Cross's "Safe and Well" wall.

3. Send in tips. Richard DesLauriers, the FBI agent in charge of Boston's office, has appealed to the public, saying, "Somebody knows who did this." If you have any information, tips, videos, or photos, you can submit them to the FBI.

4. Schedule a time to donate blood. As of today, the American Red Cross has said that it has enough blood on the shelves to meet demand. However, American Red Cross spokesperson Anne Marie Borrego told NBC News that she encourages those who want to help to schedule a time in the future to donate.

5. Keep running. Jezebel's Erin Gloria Ryan wrote on Tuesday, "The spectators-people who show up and cheer with noisemakers and high fives and encouraging cheers and magic-markered tagboard signs that read "YOU ALL ARE CRAZY! KEEP RUNNING!"-are the people who matter most to runners. If anything, the tragedy in Boston will further solidify the bond between runner and spectator. And when the Chicago marathon happens this October, I'll show up to run harder, and they'll show up to cheer louder. If anyone thought this attack would discourage the runners or the watchers, they've clearly never been to a marathon." We agree, and here at SHAPE we're challenging ourselves to keep running. Our favorite part about lacing up our sneakers and hitting the pavement is the community it fosters. We're not going to let that be taken away from us-and you shouldn't either.