The man was working inside the trench in the village of Letterston when the sides caved in. A specialist rescue crew is at the scene, along with firemen and paramedics.
More top news
The story of how Wales have taken their qualifying campaign by storm, to put themselves within touching distance of Euro 2016.
A 110-year-old All Blacks rugby shirt has sold for £180,000 at auction in Cardiff. We've been taking a look at what else you could buy...
As Super Saturday approaches it's not just us that are preparing to get behind Team Wales. Our pets are getting in the spirit too!