If somebody were to ask you to describe this poem in one word, the best word of all would be "repetition." Even though a lot of your usual forms of poetic repetition (like rhyme) are absent from this poem, there's plenty of internal rhyme and alliteration to go around.
For example, the S sound is pops up in just about every possible nook and cranny imaginable. In the second stanza, for example, you can see it in "crashes," "ears," "pleads," "zinnias," "pursues," "corners," and then in the third stanza you see it in "strikes," "stick," and "breaks." Now these are certainly not the only instances of the S sound, but they do give you an idea of how pervasive it is.
Speaking of which, did you notice that the S sound here often appears in words that make us think of violence? Check out "crashes," "strikes," "breaks," "stick," and "struggle," just to name a few. You could almost say that the S is the sound of violence (not the sound of silence), and it is everywhere.
The repetition of these S sounds, along with all the other forms of sonic repetition (such as the internal rhyme of the long I sound in the third stanza), aren't simply here for decoration. No, no. While they make an extremely violent poem a little prettier, they also reinforce the poem's major theme: violence begets more violence, plain and simple. In the same way that a violent childhood means a violent adulthood, so too one S means more of the same. Sounds in this poem, like life events, repeat themselves.