Bicyclist Killed in Collision with Tractor-Trailer in Porter Square

Cambridge police are still investigating.

A bicyclist was killed in a collision with a tractor-trailer in Porter Square around 8 a.m. Wednesday, Cambridge police say.

The truck’s driver remained at the scene and cooperated with police, while passersby told the Globe they spotted the man’s body covered with a sheet. Cambridge police have not released any additional information on the bicyclist.

Police closed several streets near Porter Square, including Mass. Ave, while law enforcement officials conduct their investigation.

Wednesday’s crash was the latest in a string of dangerous collisions involving cyclists. A bicyclist was killed in August when he collided with an outbound Fitchburg Line train while crossing a portion of tracks that cross Park Street near Prospect Hill in Somerville. In July, a dump truck struck a cyclist on the Cambridge end of the Mass. Ave. Bridge, just two months after a Coors Light truck hit a cyclist a few blocks away.