A 27-year-old man who was killed in a motorcycle crash in San Francisco on Saturday has been identified as Michael Butler, of San Bruno, according to the San Francisco Medical Examiner’s Office.

The CHP first received a report of a motorcyclist hitting the center divide of Highway 101 at 1:10 a.m., CHP officials said.

Traffic proceeded slowly past the collision before the CHP shut down the on-ramps at Van Ness Avenue and at Octavia Boulevard for about 90 minutes during the investigation.

The investigation indicated that Butler struck a catwalk on the east side of the freeway and was thrown from the motorcycle.

He was pronounced dead at the scene.