Caltrans was involved in two very different bridge demolitions last week, and has posted timelapse footage of both of them.

In the first, L.A.’s iconic 6th Street bridge is crunched by big machines while water hoses tamp down the dust, with downtown L.A. glimmering in the background. The footage compresses two days’ work into three minutes, lending the process a jangly, frenetic pace.

In contrast, timelapse of the Oakland Bay Bridge deconstruction is almost meditative. The circa-1936 bridge, already replaced by a new one, has been slowly taken apart over several years. Last week Caltrans removed the first of its trussed segments, lowering it onto two barges over the course of about fourteen hours. Caltrans’ timelapse compresses the work into almost two minutes, turning boats into swirling insects and animating the waters of San Francisco Bay.

The 2,500-ton steel bridge segments are being floated to shore for dismantling and recycling, with some of the material going to artists who applied for it through the Oakland Museum.

Rumor has it there may be a chance to grab a souvenir of the 6th Street bridge.