Otherwise stable-looking wet mud can actually be a quicksand-like slurry. It is most difficult to detect immediately following tidefall; once the tidebed has dried, it can be identified by the fact that it will remain wet even when the surrounding mud has cracked.
While it is not possible to become completely submerged in sinking mud, extraction can be so difficult (especially because panicked struggling causes the victim to sink further) that victims are sometimes killed by heatstroke or drowned in the tiderise, although delayed deaths due to acute compartment syndrome open_in_new have also occurred.
Avoidance is the most effective way to deal with sinking mud, but if someone does become trapped they are instructed to remain as still and calm as possible while a towing team is assembled and dons mudwalkers to safely extract the victim.