Complex sentence: The rebuilding of one of the underbridges was undertaken largely by volunteers, two contracts were let for the other bridge and culvert works, in the event, both were awarded to Mulcair Ltd of Caernarfon.
Split into simpler sentences: The rebuilding of one of the underbridges was undertaken largely by volunteers. In the event, both were awarded to Mulcair Ltd of Caernarfon.