According to Wikipedia:

Act 2

In her bedroom, Maria has not heard the news and daydreams happily about seeing Tony with her friends-Rosalia, Consuela, Teresita and Francisca ("I Feel Pretty"). Just then, Chino brings the news that Tony has killed Bernardo. Maria flees to her bedroom, praying that Chino is mistaken. Tony arrives to see Maria, in a fit of rage she repeatedly hits him until he finally calms her down and they plan to get away together, as the walls of Maria's bedroom disappear they find themselves in a "dream" world where everyone gets along. "Dream Consuela" sings ("Somewhere").

A grieving Anita arrives at Maria's apartment. Tony leaves through the window, telling Maria to meet him at Doc's so they can run away to the country. Anita sees that Tony has been with Maria, and asks in horror how she can love the man who killed her brother ("A Boy Like That"). Maria responds passionately ("I Have a Love"), and Anita understands that Maria loves Tony as much as she had loved Bernardo. She admits that Chino has a gun and is looking for Tony. Lt. Schrank arrives to question Maria, and Anita reluctantly agrees to go to Doc's to tell Tony to wait.

At the store, the Jets taunt Anita with racist innuendo and insults. The taunts turn into physical abuse, and Anita is nearly raped before a horrified Doc arrives to stop the boys. In her anger, Anita tells the Jets that Bernardo was right about them, and she tells them that Chino has killed Maria. Doc relates the news to Tony, who has been pacing in Doc's cellar and dreaming of heading to the country to have children with Maria. Feeling there is no longer anything to live for, Tony leaves to find Chino, begging for Chino to kill him too. Just as Tony sees Maria alive, Chino arrives and shoots Tony. As Tony dies in Maria's arms, the Jets and Sharks flock around the lovers ("Somewhere" Reprise). Maria takes Chino's gun and tells everyone that hatred is what killed Tony and the others, and now she can kill, because now she hates, too. But she is unable to bring herself to fire the gun and collapses in her grief, ending the cycle of violence. Gradually, all the members of both gangs assemble on either side of Tony's body, suggesting that the feud is over. The Jets and Sharks form a procession, and together they carry Tony away.

West Side Story