Louis XV died peacefully in Versailles on May 10, 1774. He never fleed from France at any point in his life. As a result, the "why" is unanswerable.
If perhaps the question is referring to his grandson, Louis XVI, please see the Related Question below.
King Louis the XIV - he enlarged the Palace of Versailles.
To Paris from Versailles.
King Louis XVI and Marie Antoinette were the last King and Queen of France if that helps
when the people of Paris starving and angry marched from Paris to king Louis the 16th and demanded wheat.
Treaty of Paris (1673)
so he could fall in love
Louis XIV grew up in the Tuillerie palace in Paris.
The Bastille.
That was on June 20/21st 1791.
Louis XVI lived in Versailles, his palace 15 miles from Paris.
Voltaire was jailed in the Bastille prison in Paris by King Louis XV. He was imprisoned for his criticism of the king and his political works.
Louis Charles, Prince Royal of France who died in a Paris prison.