The agency defended its efforts, saying weather, wind and environmental rules tightly limit how often these “prescribed burns” can be conducted… Some critics suggested that protests from environmentalists over prescribed burns contributed to the disaster, which came after the brush was allowed to build up for as much as 40 years. “This brush was ready to explode,” said Los Angeles County Supervisor Mike Antonovich… “The environmentalists have gone to the extreme to prevent controlled burns, and as a result we have this catastrophe today.”