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Nisqually Earthquake

On February 28, 2001 at 10:54 a.m., the Capitol shook from the seismic power of the 6.8 magnitude Nisqually earthquake. Centered a mere 17.8 kilometers northeast of Olympia, at a depth of 52 kilometers, the earthquake caused considerable damage to the Legislative Building and surrounding structures.

Within minutes after the earthquake struck, General Administration’s crews were on site surveying the damage, making an assessment of the building’s overall performance during the earthquake, and aiding in the vacating process. Also, luckily, M.A. Mortenson, the General Contractor/Construction Manager for the planned rehabilitation project, had been hired that morning and had crews on site helping with these operations.

However, complicating the situation was the fact that the 56th Legislature was in full session at the time of the earthquake. The building was at its full capacity with 455 staff members and countless other visitors, lobbyists, and tourists. The large number of surprised and at times frightened people made for a difficult task to manage. But General Administration’s crews directed this massive evacuation well and had the entire building cleared within in minutes with no injuries occurring.

Much concern was expressed regarding the dome’s condition after the earthquake. The dome was the location of a large-scale seismic upgrade directly after the 1969 earthquake, and the capabilities of these upgrades had never been significantly tested. But the dome performed remarkably well, as did the entire building during the Nisqually earthquake. The damage was substantially less than there was in comparable earthquakes of 1949 and 1965, due to the successful seismic upgrades and structural enhancement efforts of 1949,1965, and 1976. There was no significant damage to the primary structures that support the building.

The assessment noted:

• The lantern shows no signs of damage except for a stone that fell
• The foundation for the dome and the walls in the lower wings were not significantly damaged
• Stones were dislodged on the exterior colonnade buttress but the structure behind them shows no significant damage
• The North and South Porticos show no sign of stones being dislodged or structural damage
• None of the marble walls, except behind the rostrum in the House Chamber, came loose or moved significantly.
• The Tiffany chandelier in the Rotunda did not significantly move and does not show any signs of damage

The building’s structural elements came out of the earthquake architecturally strong and without the need of significant repair. However, exterior stonework was loosened, the colonnade columns shifted, and interior plasters, fixtures, and ceilings were all damaged. These ailments were to be repaired before the Legislative Building could be reoccupied. Specifically:

• The colonnade buttress stones had to be secured
• 10 of the 16 columns in the colonnade had to be secured with steel collars so that they would not fall in the case of an eventual earthquake. These columns had moved up to 4 inches during the earthquake.
• The ceiling supports in the House and Senate Chambers needed slight repairs
• Some of the ornamental plaster needed to be secured to prevent them from falling
• The wall behind the rostrum in the House Chamber cracked and a marble panel became loose and both need to be secured
• Several historic light fixtures became loose and need to be taken down
• Modern light fixtures in the Senate Chamber became loose and needed to be removed and replaced
• Plaster at the top of the columns in the State Reception Room was damaged and needs to be repaired

Urgent repairs were completed in order for the Legislature to reoccupy the building and complete the scheduled session by mid-April. Additional repair work is still required along with seismic retrofitting to protect the building from future earthquakes. These repairs and structural upgrades have been included in the general rehabilitation project that was already conceived at the time of the earthquake. The cost for these improvements has been estimated at about $10 million and will be budgeted by the Federal Emergency Management Agency (FEMA) and state matching funds.