Of course there is, and the frequency is not high to say the least, but it's not rare.
Tyson hasn't bitten the dust,
but some have counted an average of 2 professional boxers dying from injuries every year since the 20th century
Very few fighters actually die in the ring because, after all, there are referees who don't let fighters be beaten to death alive. But there are many fighters who have accumulated too many injuries in the ring and died after being taken to the hospital.
This is less common at the higher levels of the sport, where international competitions have well-established referees and medical teams who are able to separate the two sides in time and give them better treatment. On the contrary, regional fights involving lesser-known fighters have a higher mortality rate because they do not have adequate equipment and personnel; for example, more than eight fighters died in local professional fights in Indonesia between 2001 and 2004, and the WBC penalized the Indonesian Boxing Association for the deaths.