You need to provide more information. Loads, span, cross section, reinforcing, etc. A sketch would be helpful. Did the crack happen immediately after construction, when shoring was removed or after some time?
In general a crack near a support is due to a shear problem.
Jed is right.. more info would be helpful, but it definitely smells like a shear problem, and that is not good. You may want to get a structural engineer involved ASAP.
That is truly ugly. But I'd still like to see the design drawing(s) or at least a photo of the wall (beam) that shows the length, supports and some proportion of the issue. Was this a test load or just when they pulled off the shoring?
I don't want to push the panic button, but some shoring looks necessary. That's a huge crack/spall.
The photos show that the cracking is significant, but we need a lot more information to be able to assess risk.
If it cracked due to loading the beam was inadequate; a simple repair is not enough, it will need strengthening modifications.
You need an experienced structural engineer on site.
Jed and apsix are right. We can't assess why this failed without a lot more information. My guess would be that the beam was trying to transfer an offset column load, but as Jed said, a wider picture is required to get an idea of what happened. If you don't have the experience, get a structural engineer involved who does. And safety first...cordon off the area and get some shores in place, designed to carry all the load which the beam was supposed to carry.