He did not accept the request of the revolutionaries so they raged with him. It all happened at the fall of the Bastille which was a chaotic moment.
The revolutionaries butchered the prison guards and surrounded Launay. Though begging for mercy, the revolutionaries brutally stabbed from Launay repeatedly, before a crude butcher arrived and slashed de Launay's head with his machete, placing the commander's head on a spear and parading it across the district to the Hôtel de Ville, where his head was paraded and shown to the public along with that of Jacques de Flesselles