You can die on the job. In fact, 187 agents have died to date in the line of duty. However, your own death or injury is not the biggest thing to worry about. Your entire family can be put at risk.
Fortunately, death threats are not the norm. ATF agents try to prevent criminals from committing crimes; therefore, there is going to be some risk associated with the job. Raids are dangerous. ATF agents never know how someone will respond to their property or business being searched. The training that you will receive helps agents stay as safe as possible. Not to put any undue pressure on you, but if there is any way you COULD be Chuck Norris, that would be advantageous.