A rag-tag mob of anti-vaccine protesters forced the closure of the northbound lane at the Golden Gate Bridge on Thursday evening—then five people were hurt in a car crash at the subsequent bottleneck. NBC News reports that the five injured people included two California Highway Patrol officers and three bridge employees. None are reported to be seriously hurt. The crash happened at the San Francisco entrance to the bridge, where a few hundred anti-vaccine protesters had gathered for what they optimistically described as a “nationwide walkout” against vaccine mandates. California Highway Patrol spokesman Andrew Barclay said authorities blocked off part of the northbound lane after protesters threatened to “take over” the road, and video captured by NBC Bay Area shows an SUV and a sweeper truck knocking into each other at the narrow part of the lane. The truck then slammed into the crowd, injuring the five people. The cause of the crash remains under investigation.