I Want To Call CPS On A Coworker's Husband?

Okay couple weeks ago my coworker's son busted his chin she said he fell well the son had to have 8 stiches and i seen someone busted there chin before and it didnt go a little ways down his neck. now a couple days ago her other son had to go the emergency because he stood up and broke his arm i dont know anyone that stands up and breaks their arm like that. i think enoughs enough i think cps needs to go through and helps these kids out and getting them out of there situation b/c there father is soo horrable cusing at them and hitting them in the store i dont what should i do to go about calling cps