Brett Molina, USA TODAY
Google has updated its Person Finder site to assist in the search for people in Boston following two explosions that killed 3 and left at least 140 injured.
The site, which currently lists records for 4,600 people, allows users to search for a person or leave information about someone's whereabouts.
Google's service is one of several options available online for people in search of friends or family as well as for those wanting to inform others that they're safe.
The Red Cross has created a Safe and Well website where users can list themselves as safe or search for people who have already registered.
Also available: The Boston Marathon tracker, which tracks runners and offers details on when they finished the race.
Update: The Web service Twilio has set up a website for users wanting to make phone calls through the Web. Through the Call Your Family site, users input a number, then chat for up to 10 minutes through your laptop or desktop. A microphone is required.