 Three people were checked for injuries, but nobody was hospitalised.The cause was both a change to the interlocking, that failed to be accounted for in the test regime and that a temporary connection for testing had not been removed (probably added to overcome the change to the interlocking – it was entirely undocumented and unapproved) which meant that a set of points not correctly set was not detected.This allowed a proceed signal to be shown when it should not have been possible to do so.