Failure of the settlement

A complete failure of the colony would mean the death of all settlers. Possible causes can be human failure, technical failure and acts of nature beyond control. It could take decades or centuries before a subsequent colonization attempt is started. This article wants to collect situations, incidents, precautions and mitigations.

(under construction)

Destruction of life support

Temperature

If heating systems fail, the temperature in on-surface buildings may drop rapidly and destroy equipment and plants. Humans may freeze to death.

Precaution: Underground parts of the settlement draw benefit from the high heat capacity of the surrounding rock, which keeps the temperature for a long time. The interior of the settlement rooms can be optimized to store large amounts of warmth. Big water tanks have a high heat capacity.

Contamination of air or food

... with radioactive, chemical or bacteriological substances

Precaution: If dangerous substances are not produced, they can not pose a threat. If such substances are unavoidable, they should be produced, used and stored in a separated part of the colony, where no other vital system can be affected in case of an incident.

Not to be a wet blanket or antynihg but I don't know how keen Cyan would be to having a bunch of people showing up on their doorstep peeking through the windows. They are a business after all. You might want to call ahead first. BTW.. if you should get approval, I'd love to go too.. but unfortunately I'm on the east coast so that's not very feasible.

Destruction of transportation means

... that are needed to reach peripheral sites of the colony

Biological

The human metabolism need a great variety of substances. The full complexity of all interactions is not fully understood. If there is a shortage or an excess of some rather unknown substances, the health might be seriously affected. In worst case the ability to work and maintain the vital parts of the colony falls below a required minimum. Such substances may possibly produced by some sort of germs that are omnipresent on Earth, but are not in the Martian colony.

The immune system may get out of balance, since the ensemble of germs around and inside of the settlers will be different or narrowed. If, unlike in the ISS, the bacteriological profile is not updated frequently, some vital germs might become extinct.

Mitigation: A garden with soil is a living ground for many microbes and germs.