It is hard to tell from afar what may be ailing your cherry laurel.
Were they recently planted? If so, were the roots loosened and teased out from being root-bound?
Make sure that the mulch is no deeper than 2-3 inches and kept pulled back from contact with the stems/trunks/crowns of plants.
One thing that Cherry Laurel will not tolerate is wet feet (roots). Is the drainage for that one the same? Any chance there is a downspout or water goes there and keeps the soil moist for longer periods?
Your second photo shows a white substance on the soil—it's not in focus but could be a mold, which could indicate that the area is wetter and more humid, which would need to be corrected.
You can prune out the dead area.
Keep watch for sucking insects called prunicola scale, which are one of the most common problems this plant can have.
Here is our Cherry Laurel page that will guide you further:  https://extension.umd.edu/resource/cherry-laurel-identify-and-manage-problems/


Christine