University of Minnesota
School of Physics & Astronomy
Home > About > News > News >

General News

Bridge collapses close to Physics Tandem Laboratory

Photo showing the I-35W bridge collapse. The Tandem Laboratory can be clearly seen on the left.
Allen Brisson-Smith /The New York Times/Redux

The I-35W bridge that collapsed Wednesday, August 1st was in proximity to the School of Physics and Astronomy’s Tandem Laboratory. Professor Roger Rusack said that parts of the bridge came down on the Tandem’s loading dock. There were no University staff, faculty or students in the laboratory at the time of the collapse.

The police and facilities management checked the building on Wednesday evening and found it to be sound and undamaged. For the immediate future access to the laboratory has been limited to police escort only.

The Tandem Laboratory was built in 1965 to house the Tandem Van De Graaff Nuclear Particle Accelerator. Though the accelerator was decommissioned in 1978, the laboratory has been re-purposed and retrofitted in recent years. The building currently houses some experiments such as Rusack's Compact Muon Solenoid APD Long Term Gamma Study. Bill Gilbert, Electromechanical Systems Specialist, said that this experiment is still working although he has not been allowed near the building. "We know it's running because we can check it over ethernet."

Professor Bruce Hammer of the Department of Radiology, which shares the Tandem Facility with Physics, said that his experiment also survived the accident. Hammer said that none of his staff were on site at the time of accident. He was allowed briefly back into the building on Thursday morning so that he could perform necessary maintenance work on his experiment, but was evacuated shortly thereafter for safety reasons.

More information at