Severe Dehydration

What are the symptoms just before death to severe dehydration?

And how does severe dehydration kill a person exactly?

Would anybody happen to know?

Severe dehydration

Untreated mild or moderate dehydration can lead to severe dehydration.
Severe dehydration is a medical emergency and requires immediate medical attention. You should seek medical attention if you or your child has any of the following symptoms:
dry, wrinkled skin that sags slowly into position when pinched up
an inability to urinate, or not passing urine for eight hours
irritability
sunken eyes
low blood pressure (hypotension)
a weak pulse
a rapid heartbeat
cool hands and feet
fits (seizures)
a low level of consciousness
feeling tired (lethargic) or confused
blood in your stools (faeces) or vomit
If not treated immediately, severe dehydration can lead to complications. You can even die from severe dehydration because the blood stops circulating. If you experience this level of dehydration, you may need to be admitted to hospital and be put on a drip to restore the substantial loss of fluids.

NHS: Dehydration