They may have been using heavy equipment like jackhammers or those tamping machines and had on hearing protection, but they really should have had a protocol so at least one person was on alert for messages (unless somehow the bridge operators didn't know they were there?)

Christ. I get that hindsight is 20/20, and this was not a usual or expected situation, but there really should be a way to give enough warning to prepare. And I really hope this isn't a case of valuing workers so poorly that it didn't even occur to someone to warn them.