Some engineering students from the University of British Columbia are taking the credit and getting the blame for hanging a Volkswagen Beetle from San Francisco's Golden Gate Bridge on Monday.

They say the aim of the stunt was to promote UBC's engineering program.

In press releases faxed to San Francisco news media, the students say they wanted to "draw attention to the masterful feats of professional engineers and to celebrate the skills of the tradespeople who built the bridges."

The students said the incident was also designed to commemorate the 20th anniversary of a similar prank in Vancouver, where engineering students annually suspend VW bugs from bridges.

"Sank like a stone"

The red bug with an "E" for engineering and a Canadian flag painted on the side dangled 30 metres under the bridge for about five hours, before workers cut it down.

A spokesperson for the San Francisco Bridge Authority says the car "sank like a stone" after its tethers were cut.

The stunt caused a major traffic jam, as morning rush-hour commuters slowed down to gawk at the spectacle. But they had to look hard. The entire bridge was shrouded in thick fog.

San Francisco's Highway Patrol is investigating the incident, and says charges could be laid.