I'm thinking the same thing. One of them could have gotten sick, somebody could have been injured, they could have been involved in an accident, they could have been victims of a crime. I agree that it was most likely their fault, but since none of us knows the facts, we really can't be sure.
So you're saying that the police were at the construction site then went to the ends of the bridge to stop traffic? This doesn't align with the story that a police officer was about to drive onto the bridge to warn the construction workers. If the police were at the construction site, it seems like they would have warned the construction workers first.
You might consider asking the mods to change the title of this thread. I would guess a lot of people think it might be a technical question specifically about Apple brand watches. The thread really is not just for people that use Apple watches. It could be any smartwatch.
I'm not suggesting that this is the case for anyone here, but drinking alcohol can lower respiratory rate. If people are drinking more alcohol than they otherwise would, that might explain it.
It's unclear if you are asking why they were on the bridge at night, but if you are, a good reason would be so that they could close traffic lanes while they work, with minimal impact on traffic.