Final answer:
Jacques-Germain Soufflot died before Le Panthéon was completed due to his death in 1780.
Step-by-step explanation:
Jacques-Germain Soufflot died before Le Panthéon was completed due to his death in 1780. He was the original architect of the Panthéon and designed its neoclassical style. After Soufflot's death, Jean-Baptiste Rondelet took over as the chief architect and completed the construction of the Panthéon.