The first 22+1⁄2 miles (36 km) of line, from Paddington station in London to Maidenhead Bridge station, opened on 4 June 1838. When Maidenhead Railway Bridge was ready the line was extended to Twyford on 1 July 1839 and then through the deep Sonning Cutting to Reading on 30 March 1840. The cutting was the scene of a railway disaster two years later when a goods train ran into a landslip; ten passengers who were travelling in open trucks were killed.