Adriana La Cerva (Drea de Matteo) is the subject of one of The Sopranos' more tragic deaths, but it needed to happen. As one of the few main characters not directly in the Mafia, Adriana knew enough about the mob's inner dealings as Christopher's (Michael Imperioli) girlfriend-turned-fiance to be used as an informant for the FBI. Adriana's fate as an FBI informant became sealed with her friendship with Danielle (Lola Glaudini), who turned out to be Special Agent Deborah Ciccerone going undercover. By the time Deborah reveals herself, the FBI corner Adriana to become an informant to avoid jail time for drug distribution at her nightclub, Crazy Horse.
Being an FBI informant corrodes Adriana with extreme stress, but she remains hopeful that the FBI can fulfill its promise of getting her and Christopher out of the Mafia life. Attempting to avoid a fate given to other informants like The Sopranos' Jimmy Altieri by only giving away information that she didn't deem crucial, Adriana hopes that she can appease both sides. Unfortunately, her efforts are to no avail, since Tony Soprano (James Gandolfini) eventually finds out and puts a hit on her. Like many Mafia deaths, there's a cover-up for Adriana's disappearance that insists that she ended her engagement with Christopher and moved away.
Finding ways that helped both herself and Christopher create a better life, Adriana was one of the few more selfless Sopranos characters. For that reason, she created a sense of hope that one can survive the unforgiving mob world. For this reason, her death becomes all the more devastating. However, Adriana's death in The Sopranos makes the important point that despite being cared about by higher-ups like Tony and Christopher, even Adriana isn't immune to the mob's corruptive, dangerous tendencies. The Sopranos notes how following the Mafia code by killing Adriana shows how corrupt and unchanging the code is, even when it creates more consequences than it eradicates.
What If Adriana Had Lived?
Adriana's survival would have created an entirely new message about the Mafia that The Sopranos never intended to create. One of the most important points that The Sopranos makes is how inescapable the Mafia is, whether it be due to the piling crimes that one has to commit while serving in the mob or the abusive mental prison that it creates for adherents. Sometimes people find a natural belonging in the Mafia world, like The Sopranos' Furio (Federico Castelluccio), but Adriana represents someone who is still negatively affected by the mob despite holding an outside position. If Adriana lived, she would have received her wish of escaping, which The Sopranos argues is not feasible.
Proving the unfeasibility of such an escape from the mob world, The Sopranos sets up the impossible logistics of Adriana's survival well before her death. In The Sopranos season 1, episode 5 "College," Tony goes out of his way during a college-touring road trip with Meadow (Jamie-Lynn Sigler) to kill an FBI informant who went into the Witness Protection Program. Likewise, the Witness Protection Program wouldn't protect Adriana from being hunted down by the mob. Only one Sopranos FBI informant, Ray "Buffalo Ray" Curto (George Loros), doesn't suffer the usual consequences of a Mafia rat, but he only becomes the exception to the rule because he dies of a stroke before the Mafia finds out about his secret. Therefore, Adriana's death in The Sopranos was not only logical for her arc, but it was also in line with the show's core themes.