Q: "Daddy, what happens when you die at the hospital?"

A: " They clean the bed and admit another one".

The body has many cascades of failure, the net result is cardiac arrest. Now cardiac arrest is just medical death and it can occasionally be reversed through resuscitative efforts depending on a myriad of factors. Legal death is when you are beyond salvage.

Your cells need sugar and oxygen to make energy to operate the Sodium/Potassium pumps to keep the sodium out, when the pumps stop sodium floods the cell and causes lysosomes to explode due to osmotic gradients- this releases digestive enzymes into the interior of the cell causing it get eaten from the inside. Thats cell death.

Now your brain is the main user of energy, when blood flow slows to a critical level, the neurology starts to get disregulated causing your autonomic nervous system to spazz out driving your organs through predictable stages of disregulation and failure.

The lungs start to fail from the lack of blood flow causing more blood to bypass them without picking up oxygen- this aggravates the above. Also causes permanent damage to the lungs.The build up of CO2 causes your blood to become more acidic - which accelerates organ failure and cardiac and neurological disregultation leading to failure.

Your kidneys are very sensitive to blood pressure being in the right zone, when the BP gets too low your kidneys fail- causing a rapid build up of metabolic wastes and an electrolyte imablances- this effects all the organs - most critically the heart muscle and muscles of reapiration - both very sensitive to Sodium/Potassium levels.

The slowed blood flow in the tissues causes local acid/base balance disregulation which cause clotting in the capillary beds - you end up with disseminated intravascular clotting- which accelerates all of the above.

The above doesn't include any of the hormonal disregulation that accompanies the cascade of failure.

Eventually, you endup with seizure, coma, death.