At the commencement of the year 1925 the Post Office authorities, for the purpose of laying down telephone lines, were making a trench from the corner of Rochester Road (Camden Town) north-eastward up the Camden Road and across it into and along Murray Street in the direction of St. Paul's Road, and were laying ducts at the depth of about 10 ft. The distance from the corner of Rochester Road to a point opposite the corner of Murray Street is 160 yards, the direction north-east, with a slight rise in that direction. Previously the London County Council tramway cable ducts had been laid down to the depth of 3 ft. 6 in., but below this level the whole of the ground excavated was in an undisturbed state. The trench was 2 ft. 7 in. wide. A man-hole had been sunk at the corner of Rochester Road, another at the end of the works on the Camden Road, and a third opposite to it at the corner of Murray Street, all to a depth from the surface of more than 12 ft. In fact the Camden Road man-hole was sunk to the depth of 15 ft. 6 in., so as to enable the excavators to tunnel under the road to Murray Street in order that the stream of traffic along the Camden Road might not be disturbed.