Massive fat mounds removed from London's sewers

Thames Water says it has removed enough fat to fill nine double decker buses from London's sewers.

The company said the clean-up operation, beneath Leicester Square, was the largest of its kind.

The build-up of fat, caused by people pouring substances like cooking fat down the drain, causes flooding in 7,000 homes in the capital every year, Thames Water added.

Daniel Brackley from Thames Water explains what has to be done to remove the material.