James Thompson, MD, who happens to be a fellow asthma experts (well, he's a well established asthma doctor, so he's actually far more expert than I'll ever be), gave an answer so brilliant that I couldn't possibly word it better, so I wont. Dr.Thompson's answer to this question is:
If I were forced to give a one word answer I would say, "Yes". Fortunately I can elaborate and tell you that although asthma can be fatal, the majority of people with the diagnosis of asthma do not die. In the early 1990s there were more than 5000 deaths per year attributed to asthma in the United States. Data from the about three years ago approximated about 4000 deaths annually (and falling). The bad news is that there are still people that die from asthma. Furthermore, the more than 20 million people that have asthma in this country are more affected by the impact of the disease on their quality of life.
Mortality and morbidity (in other words death and poor quality of life) are greatly reduced when asthma management is appropriate. Well controlled asthma leads to minimal impairment from breathing problems no limitations on activity, and a duration of life that is equal to someone who does not have asthma.
So, yes you can die from asthma, but good asthma management can prevent it.