Are you sure about the number of houses destroyed?
I visited Los Alamos to see friends a few years ago. They pointed out the area where houses burnt down. Seemed like no more than 20-30. Perhaps the 200 was number of houses damaged.
Dave is correct.
The Cerro Grande Fire was a disastrous forest fire in New Mexico, United States of America that occurred in May 2000. The fire started as a controlled burn, and became uncontrolled owing to high winds and drought conditions. Over 400 families in the town of Los Alamos, New Mexico lost their homes in the resulting 48,000 acre (190 km²) fire. Structures at Los Alamos National Laboratory were also destroyed or damaged, although without loss or destruction of any of the special nuclear material housed there. Amazingly, there was no loss of human life. The US General Accounting Office estimated total damages at one billion US Dollars.
10 May 2000 The town of Los Alamos was evacuated at noon. That evening, 235 homes in Los Alamos were destroyed.
The difference in numbers (400 families vs. 235 homes) is that a lot of the homes destroyed were duplexes and four-plexes in use from the earliest days of the lab.