I’m looking for an experienced contractor’s view on this simply because I don’t know how this is built. Yes, I called it out in my report and recommended a contractor look at it. The crack between the arch and the horizontal brick above is large and at first glance would recommend any crack in the siding be repaired or sealed. But this is brick and I don’t know how it’s supported. Is there a lintel used when building something like this? 3/4 if the face of the brick is visible from below and the 1/4 that isn’t is overhanging the trim. Meaning the only support from below is the trim board. If the arch is the support, that would mean the brick above is no longer supported. Can anyone here with experience with this type of construction tell me how serious this really is? I pressed gently but firmly and stopped when I felt a slight give. This looks like a disaster waiting to happen.
^^^^ What Larry said, plus the possibility of heat/cold expansion and contraction of the lintel itself could have caused the separation.
There is only one way to support cavity wall brick masonry above a door or window opening, and that is with a properly sized lintel. And anything made of wood or magic is a poor choice for a lintel.
What you have there is basically a slow motion train wreck.
I can’t believe some of the stuff that passes for modern construction.
I saw no evidence of a lintel and you can see in the pictures that there is nothing below the arch supporting it. I guess there could be one below the horizontal brick but then what would the brick arch adhere to? I’m not a brick mason but I’m pretty sure that the mortar isn’t going to adhere to metal. On my way out of the neighborhood, I looked at about 8 more homes with the same garage arch and saw no cracks. Based on that I think it’s more of a construction flaw but regardless of the cause, this seems to be a hazard. Is there some sort of support or fastener that I am not seeing?
To me it looks like that trim board is holding it up. That is no bueno.
How old is the development?
The home was built in 06. The neighborhood was started in 04.
Thinking that I’m starting to side with @dtews here. Notice the patch work on the left corner?
Honestly to me it looks like the builder couldn’t get his hands on a steel segmental arch lintel, and cobbled some bullsh-- together for this house. There are suppliers out there that sell these arched lintels. My guess is the development probably has a bunch of arches done the correct way with the lintel the architect specified, but for whatever reason the builder didn’t have one for this garage, and he put together some ad-hoc nonsense to make it look like it had a lintel.
If this were my client, I’d tell him it needed to get redone correctly. Probably looking at a $15,000 job to put the right lintel up. A lintel that size is probably $2,000-ish.
If it were my client, I would just refer them to a masonry contractor and let them deal with it. 
I’m with you. If you look closely, the peak of the arc is about a foot to the right of center. I actually counted bricks and there are 60 across the top. Brick 30 is a foot from the peak of the arch. Yeah, too much time on my hands 
To me that just confirms that an actual arch lintel wasn’t used. Would you state this as a safety hazard? I already have but haven’t submitted the report so I am open to outside opinions.
That was the plan. I’m just thinking that this is also a safety hazard. Not knowing how this was constructed I don’t want to raise undue alarm.
Yes, I would. Gravity is already pulling on it, and it won’t stop.
I wouldn’t at this point. Just note the separation in the mortar and recommend further evaluation. Don’t raise any undo red flags without fully knowing what the cause may be.
The fact that there’s three tubes of caulk along the top of the soldiers kinda spills the beans, don’t-cha think?
Maybe… 
Whenever the garage door opens and closes, it vibrates the wall, loosening the bricks.
You’re positive it’s not a brick veneer ?
Looks like after market weep holes that might not have made it through, moisture getting caught up behind that brick and then swelling the metal lintel causing cracks.
How do we know it’s a wooden arch holding that up only ? I reckon the damage would be worse given the age of the house.
Insight would be appreciated
It looks like brick veneer to me…
Sure looks like that white piece of trim under the arch is sagging or pulling downward compared to the horizontal weather seal at the backside of the top of the opening. This coincides with the larger separation of the solider bricks toward the center of the opening. I wouldn’t bat an eye calling this a safety hazard. Make the buyer spend a few hundred bucks for an engineer evaluation or make them flush their hard earned money down the toilet that is the american health care system when the bricks fall on their head? Sounds like an easy choice to me.