Two symbols that appear at various points are the tire and television.
Rolf becomes very involved with Azucena’s survival and hopeful rescue. He tries various tactics to release her from the mud, but has to admit that she is truly stuck. More than the mud, such as rubble or even other bodies, is holding her from below. He finally uses an old tire to prop her head up, and her head manages to stay out of the mud for a couple days. She does finally die, but not from drowning. The tire stands for hope.
Because Rolf has decided to help Azucena, he sets aside his role as cameraman. Although there are other news crews there, Rolf stops shooting. Yet because of the television, his girlfriend back home (the narrator) can see and hear the tragedy unfold. Although Rolf is not speaking directly to her, she maintains communication. Television stands for transformation. Rolf changes because he gives up his camera; he is not using the same mode of communication, and his reflections are part of what alters him. At the same time, because the narrator feels close to him and the others on the scene, she projects her story-telling power onto him. He remembers some of the stories she is always telling him, and in turn tells them to Azucena. Here as well, his personality changes by taking in some of his girlfriend’s identity.
One of the central symbols of this story for me at least is the pump. This pump and its unattainability seems to be a symbol of the real lack of compassion and care of humanity in the face of suffering. Consider the following passage:
In the meanwhile, more television and movie teams arrived with spools of cable, tapes, film, videos, precision lenses, recorders, sound consoles, lights, reflecting screens, auxiliary motors, cartons of supplies, electricians, sound technicians, and cameramen: Azucena's face was beamed to millioins of screens around the world. And all the wile Rolf Carle kept pleading for a pump.
Note how a very short and simple sentence is placed after a long sentence which lists all the sophisticated technology that reporters bring with them. They are able to do incredible things thanks to technology, but somehow bringing a pump to save Azucena eludes them.
You might want to think as well about how Azucena herself might be a symbol and what she symbolises. This should start you off though - good luck!