What is the principle of ministerial responsibility?

Ministerial Responsibility is a concept, developed out of the Westminster system in the UK, wherein the Minister of a particular branch is the one ultimately responsible for the actions of that branch.

This is important as it means that the government doesn't need to hold a vote of "no confidence" if one ministry fails. Instead, that minister could simply be removed and the government could continue.

mount st. helens in washington erupts, causing a massive avalanche and killing 57 people on this day in 1980. ash from the volcanic eruption fell as far away as minnesota. seismic activity at mount st. helens, which is 96 miles south of seattle, began on march 16.