Great Western Coffee Shop

Broad street/Sloper Road/Leckwith Road by ninian park train station

No one injured(thankfully) as it was an ECS and I presume not running under its own steam

it appears it was being towed, and maybe the bus front wheels were slightly higher than normal

 and this is why the bus did not have enough height to clear the underside of the bridge

Passengers forbidden on any towed vehicle

? How do the seaside road trains such as the one at Weymouth work then ?

Um yes. I see the dilemma.
If it died when in service, passengers will be transferred to another service vehicle.
The dead vehicle will then be towed somewhere - with no one on board.
A rephrase to read "No passengers permitted on an out of service vehicle when under tow".

I believe that legally no passengers are permitted on any out of service vehicle.
 

The police pictures (https://www.walesonline.co.uk/news/wales-news/live-updates-double-decker-bus-27110053) show the bus being towed using a solid bar, and with its front suspension raised. At first sight that looks odd, but the bar is very tight under the bodywork at the front, so I guess the suspension was jacked up (by some internal means) to stop it fouling. If that's the case, then it's going to be fairly easy to identify someone to blame.

I presume we all could tear ourselves away from our local west country news

 and tune into ITV Wales at 6pm and BBC1 Wales at 18:30pm

to see some better images

Presumably the same as empty stock trains.  They usually run with a 5xxx head code.   A few years back when some local schoolchildren were treated to a trip into the newly extended Bedwyn turn back siding the head code was changed to 1Zxx. 

I assume that the bus normally fits under the bridge.  Heavy recovery usually lifts the front axle a couple of feet up to clear the road for towing. Is that what made the bus over height? Finger of blame should be pretty straight if so.

As I said, the picture (really from WalesOnline (https://www.walesonline.co.uk/news/wales-news/live-updates-double-decker-bus-27110053)) shows the bus with a solid tow - but there's no way to know if that's how it got there or if it's being recovered.
(https://i2-prod.walesonline.co.uk/incoming/article27110021.ece/ALTERNATES/s510b/0_WhatsApp-Image-2023-06-12-at-205931jpeg.jpg)

Bus 342 is listed as a Scania N230UD Omnicity double deck, so is almost certainly 4.38 m (14'5") high. The bridge is marked as 4.5 m (14'9"), so it ought to fit. The model has (as an option, I think) a Suspension Raise / Lower Facility (Ferry Lift). Other than that, something else not in the story or pictures must have made it higher, though not by very much.

BBC Wales did not even cover the story,

not sure if ITV Wales covered the story as I could not get ITV Wales local news.

'Minor news item not covered by major news outlets - shocker' :P