I always say to nervous pax that you are more likely to get killed travelling too/from the airport, perhaps I should update that to too/from the AIRCRAFT!
The bus service at LGW is provided by a company called AIRLINKS which is a partnership between National Express and BAA. Never before have I heard of such a thing happening at LGW and I sincerely hope for the bus drivers sake that it was a mechanical failure of the bus and not a brain failure of the drivers in failing to set the handbrake.