Natasha stops at a crosswalk ahead of Daniel, and he assures the reader that he's not following her. She has her headphones on and is lost in her music. Daniel is right behind her as she steps off the curb. She doesn't notice that a white BMW is running the light. Daniel pulls her backwards, and they fall on the sidewalk.
Daniel's narration suggests that he already feels very close to Natasha despite the fact that he doesn't even know her name, illustrating a very different and entirely opposite worldview than the one Natasha holds.
Natasha notices her screen is cracked and remarks that the guy in the BMW almost killed her. Daniel asks Natasha if she's okay. She asks if Daniel knows how long she's had "this," and he realizes she's cradling her broken headphones. She looks ready to cry, and Daniel offers to buy her another pair. He's desperate to make her stop crying—he can't help but cry when someone else cries. She refuses as Daniel tries to make her laugh, and he tries to hide his tears.
Daniel's tendency to cry when others cry is another way the novel shows that people are intrinsically connected—Daniel very literally feels and experiences others' emotions as his own. Notice too that now that Natasha's headphones are broken, she has to actually talk to Daniel and is also showing him actual emotion while she does so.