Incident pit

An incident pit is a conceptual pit with sides that become steeper over time and with each new incident until a point of no return is reached. As time moves forward, seemingly innocuous incidents push a situation further toward a bad situation and escape from the incident pit becomes more difficult. An incident pit may or may not have a point of no return such as an event horizon. 
It is a term used by divers, as well as engineers, medical personnel, and technology management personnel, to describe these situations and more importantly to avoid becoming ensnared.
British Sub Aqua Club Diving Officers Conference 1973.
The Incident Pit concept was introduced as part of British Sub Aqua Club Diving Officer's Conference Report on 8 December 1973 by E John Towse, Chairman of the BSAC Diving Incidents Panel. The Pit was first described by Towse at a Diving Medical Conference at Stoke Mandeville Hospital organised by Dr John Betts earlier in 1973. The following is an extract from the report.
In popular culture.
"Pushing Ice", by Alastair Reynolds, uses incident pits as a key plot points in the context of an Interstellar Ark.