To burn bridges is to end relationships so badly you can never go back. Do not burn bridges, burn bridges on the way out, burn bridges with an old employer.
It is nearly always advice against doing it, since the loss is usually the leaver's. The picture is from an army destroying the bridge behind it so retreat is impossible.
1phraseburn bridgesTo end relationships so badly you can never go back.
“Resign politely and do not burn bridges you may need.”
burn bridges is a phrase.
Also accepted in games: burn your bridges
Practised in Idioms