Yes. There was a death last year in South Carolina (Angela Chadwick Hawkins) when a device used for starting fires blew up.

According to one article [1] there were 6 deaths from prescribed burns between 1963 and 2013 (and 201 deaths from undesired wildfires). While looking this up,I was also surprised to learn that the #1 cause of death when fighting wildfires is vehicle accidents, and the majority of those are plane crashes

[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4605741/