The Red Cross says the best way to help right now is to get in touch with loved ones through its Safe And Well Listings. The organization is not asking for blood donations at this time.

The Salvation Army is offering food, beverages and crisis counseling to survivors and first responders. Find out how you can get involved here.

Boston Mayor's Hotline for families of victims: 617-635-4500

Boston Police line for witnesses who may have information: 800-494-8477

Anyone with info about the incident: 1-800-494-TIPS