Tonnes of earth dropped onto the track as the tunnel underneath the development fell in yesterday evening. Tesco is understood to have launched an investigation with its contractors and promised to work with the authorities to get rail services back to normal as soon as possible.
A Tesco spokesman said: 'Following last night's tunnel collapse at the site of our Gerrard's Cross development Network Rail and the project's civil engineers, Jacksons, are investigating the cause and working round the clock to get trains running again. Thankfully nobody was hurt and whilst the experts on the ground are rightly running the incident we are helping in any way we can.'
The store is in the very early stages of construction. The finished store will have 20,000 sq ft (1,860 sq m) of selling space.