An overhead cable on the Midland Metro has been knocked out of place, forcing trams to be cancelled and a replacement shuttle tram to run a shorter route in their place.
Around six services were cancelled between Wolverhampton and Wednesbury Parkway since the damage to the line was spotted at 2.10pm today.
National Express, which runs the Midland Metro, instead offered a shuttle tram between Wolverhampton and Priestfield.
Passengers who wanted to stop between Wednesbury Parkway and Priestfield however needed to transfer onto National Express bus service 79 at Wednesbury Bus Station, Great Western Street, using their Metro tickets.
Jack Kelly, spokesman for National Express, today said CCTV camera footage of the line was now being reviewed to see how the damage had been caused.
He added: "We're still trying to determine what has caused this. Something has brought a cable out from where it should be.
"We will now have to look through the CCTV."
He said the hope was that the normal tram service would be resumed before peak evening times of people leaving work.