Here are three important tips and websites in the wake of what happened yesterday at the Boston Marathon.

1. The Boston Mayor’s hotline if you’re looking for a loved one is 617-635-4500.

(And both the Red Cross and Google have set up websites to help connect people with their friends and family in Boston.)

2. It’s best to text people in Boston rather than call them. The cell towers there are overloaded, and it helps to keep them open for emergencies.

3. The Red Cross says they have enough blood AND enough money to handle the crisis. Instead of donating blood now, wait for a few weeks or months. You can still donate money, but make sure you go to the source and watch out for scams.