Water pumped from dangerous lake in French glacier

Work has started to drain a huge lake that has formed under a glacier in a popular skiing area in the French Alps.

Enough water to fill 26 olympic sized swimming pools is beneath the glacier more than 10,000 feet up Mont Blanc on a popluar path for climbers.

In an attempt to prevent a repeat of a flood which killed 175 people more than a hundred years ago, engineers in France have started drilling into the glacier to prepare to pump out the water.

The operation, costing almost 2 million euro, is expected to last until October.

A tram route used by climbers in the area was shut down after scientists told local authorities about the trapped water.

An alarm system has also been installed, which gives residents between 10 and 30 minutes to evacuate if there is flooding.

Water from the glacier has devastated the valley before.

The mayor's office said the amount of water trapped is similar to that in 1892, when flood waters, which burst from the buried lake, devastated the valley.

When pumping starts, it will relieve pressure inside the glacier.