A testbed for structural health monitoring uses the embedded 72-sensor seismic network in the UCLA Factor building which records continuous data at 500 Hz. In addition, a 15-station prototype wireless seismic monitoring array has been developed and tested. It is based on the Crossbow mote technology and will be run side by side with digitzers in Factor for comparison.The Mica-2 mote network is controlled by Wisden software and is designed to monitor local areas such as buildings. Data from the wired building array have been used to compute time-varying displacements in 3D, to compute the finite impulse response of the building during the 9/28/04 Parkfield and 12/16/04 Santa Monica Bay earthquakes, and to apply time series analysis techniques to long time series and stacked spectra to identify the higher modes of vibration. Modes of building vibration are found to decrease in frequency at the times of large amplitude shaking by earthquakes or wind.