If you've read Romeo and Juliet, you probably have a pretty good idea how this one ends, and as much as we love Tony and Maria, a future really just isn't in the cards for them. Anita, angry about her treatment by the Jets, gets a phony message to Tony saying that Maria was killed. A grief-stricken Tony tells Chino to kill him too, and Chino obliges. Kleenex all around, and try to keep from sobbing in the lobby, kids.
Romeo and Juliet ends in a similar way, with Juliet faking her death, Romeo not getting the message and thinking she's really dead, killing himself. Juliet wakes up to see him dead, and joins him for real this time. Maria, however, survives.
MARIA: All of you! You all killed him! And my brother, and Riff. Not with bullets, or guns, with hate. Well now I can kill, too, because now I have hate!
At the end of R&J, the feuding Montagues and Capulets come to their senses and reconcile after they find the two doomed lovers lying dead in the family tomb. West Side Story echoes that ending, as the Sharks and Jets put aside their differences for a while to gently carry poor Tony off the playground pavement.
While Shakespeare's warring families seem to call off their feud for good, we don't get that same feel from the Jets and Sharks. The underlying issues are probably too entrenched to keep the ceasefire going, and our guess is that the boys will be back hating on each other in no time.
Some people thought the creators of West Side Story wimped out by keeping Maria alive at the end of the film. She had the gun; she could have killed herself like Juliet. But they couldn't go through with it. That's Hollywood, folks. We love ourselves some happy endings.