Who killed Sonny Corleone?

Can you shed some light on the enigmatic question, "Who killed Sonny Corleone?"? This query has been a subject of intense speculation and intrigue within the world of popular culture, particularly within the realm of the iconic movie franchise, The Godfather. From the brutal attack on Sonny's life to the subsequent investigation that ensued, the mystery surrounding his death continues to captivate audiences to this day. So, who do you think was behind the hit that took down the formidable Sonny Corleone? Do you have any theories or insights that could shed light on this long-standing mystery?