Report on the Brush Fire at LIGO Hanford Observatory
by Fred Raab, Head of LIGO Hanford Observatory
June 29, 2000

LIGO Hanford Observatory Home
NOAA satellite photo
NOAA Satellite Photo

Last night the LIGO Hanford Observatory survived an intense brush fire without damage.The brush fire was started approximately 20 miles southwest of LIGO by a fatal car/truck collision on Tuesday. As of Wednesday afternoon it had jumped Highway 240 and was headed northwards, driven by high winds, toward the tank farms of the Hanford 200 area. At 6 pm, with the fire still about 10 miles west of LIGO and heading northerly I went home for dinner. Sometime after 7 pm I noticed the sky grow ominously dark over Richland and I began preparing to return to the observatory to check on conditions, suspecting the winds had shifted.  Richard McCarthy and I learned through Hanford emergency personnel that the fire was racing toward LIGO. Richard called the lab to tell people working inside and a touring Boy Scout group to evacuate the site. I drove in to ensure all personnel were out and Richard followed shortly to actuate our groundwater pumps and valves to recharge our firewater tanks.

View of approaching flames
View from Corner Station Roof

I found the site evacuated, except for Doug Cook, our laser safety officer, who had just completed a walk-through of all the labs and assured me that all personnel and visitors were gone. Hanford Fire had set up a command post on the site, with a large number of fire engines, earth moving equipment attempting to trench firebreaks around the 10 mile perimeter of LIGO, and aircraft dropping fire retardant on the most threatened structures. By this time the winds had grown extremely strong with a wild fire out of control and bearing down on the observatory. For a time, the Y arm of LIGO served as a firebreak, but the winds eventually blew the fire over the arm and it raced further across the Hanford site. The fire started racing along the Y arm past the mid and end stations. McCarthy and I went to the well (at the Y end) to actuate the fire recharge system and were able to inspect those buildings at that time. The fire had burned out all the available fuel on the shrub-steppe surrounding these structures without damage to the structures. When we returned, the fire was challenging the corner station. I was able to inspect the site from the platform on the corner station roof and could see a line of fire advancing toward the X arm, but then a wall of smoke and high winds drove me off the roof. The combination of the extensive rock works we had installed surrounding our buildings and the firefighter's efforts prevailed as the fire burned down most of the grass and sage near the vertex, without placing significant heat loads on the buildings themselves. By this time I could see fire extending several miles to the east, about 15 miles to the west, about 10 miles south and ascending Rattlesnake Mountain. The corner station was about the safest haven around, so we remained there.

Aerial drop of flame retardant chemicals
Aerial Drop of Fire Retardants

As the fire advanced along the X arm burning away from the corner station, the firefighters rapidly left our site. I later found out that this was when the fire turned up the Yakima River valley, headed for populated areas of West Richland and Benton City, which were under evacuation orders. We remained, predominantly at the corner station, inspecting fire conditions with binoculars as the fire burned along the X arm toward the end station. The fire failed to jump the X arm and by midnight, it had burned past the X end station. We were able to drive out on the X arm at this time and inspect those buildings, which looked OK. The winds were shifting and the fire started to advance northerly again. I expected it to start burning back toward the corner station along the north side of the X arm, but I knew our roads would provide adequate fire breaks. We decided conditions looked good enough to leave the observatory by driving north to the Wye barricade and then to Richland along Stevens Way.

Beam tube covered with flame retardants
Beam Tube Covered with Fire Retardants

By morning the fire was mostly contained on the Hanford site, but was burning near populated areas. The population of these areas was evacuated to emergency shelters. According to radio reports, about 500-1000 firefighters were on the fire, which had by now burned about 150 square miles of land. We instructed staff to remain at home while a few of us drove out to do an inspection under daylight conditions and to attend to checking systems. A power surge around midnight had taken down our turbo pumps (without any danger to the vacuum system) and we began a restart procedure. We drove the full 10 mile perimeter of the buildings and beam tube and found no discernible damage. We met with Rex Jordan and other officials of Hanford Fire and other DOE contractors who came out to inspect conditions at LIGO. The Y end station was partially covered with fire retardant compound, whose sticky surface had a layer of ash glued onto it. I think the worst damage we may have is if the fire retardant damages the underlying paint. Otto Matherny is trying to get a contractor out as soon as possible to wash this down. The ventilation systems prevented smoke damage within the critical experimental areas although there is a slight smoke smell and dust levels were exceeded in the clean areas during the fire. None of the critical optics were exposed. Vacuum system operation has been restored to normal.

Burned area between beam tube arms
Burned Area Between Beam Tube Arms

The DOE contractors, especially Hanford Fire and Hanford Patrol, were exemplary in their efforts to keep us informed, to let key people into the affected areas while providing for public safety, and most importantly to bring tremendous resources to bear on protecting our structures. As of approximately 10:30 am PDT today, the state of emergency surrounding the LIGO area was lifted and roads into the area were opened. Some personnel are returning to resume installation/commissioning work.