A teenage girl who jumped from a footbridge over a major road was saved by a member of the public who managed to grab her arm - and a probationer police constable who risked his own life by dangling alongside her until more help arrived.

The drama unfolded this morning at the bridge over the A40, near Swakeleys Roundabout in Hillingdon. Scotland Yard said officers had only just arrived when the girl, in her mid-teens, jumped from the bridge.

A member of the public managed to grab her arm through the safety rail of the bridge and held on. Dewayne Hamilton then vaulted the railings and put his arm around the girl to stop her falling.