what does "killed and went away" mean?

I am learning this course Stanford CS224N: natural language processing with Deep Learning.

The professor is saying

on the one hand, whenever you see these pictures you should hold onto your wallet. Because there's a huge amount of detail on the original vector space that got completely killed and went away.

is it the vector space got completely killed?

what does the phrase "killed and went away" mean in this context?

In the professor's example, there are 2 following vector spaces,

VS1: original vector space, which is a 100-dimensional space;

VS2: a 2-dimensional space, into which original information are being projected down.

During the projection, some information in original vector space(i.e. VS1) would be lost.

Phrase "killed and went away" here means "lost".

Some knowledge about linear algebra is needed to under this.