In 1878 a Thames pleasure-steamer, the , collided with the collier "Bywell Castle" and sank, causing over 650 deaths. The accident took place close to the outfalls and questions were raised in the British press over whether the sewage was responsible for some of the deaths. In the 1880s further fears over possible health concerns because of the outfalls led to the MBW purifying sewage at Crossness and Beckton, rather than dumping the untreated waste into the river, and a series of six sludge boats were ordered to ship effluent into the North Sea for dumping. The first boat commissioned in 1887 was named the SS "Bazalgette"; the procedure remained in service until December 1998, when the dumping stopped and an incinerator was used to dispose of the waste. The sewers were expanded in the late 19th century and again in the early 20th century. The drainage network is, , managed by Thames Water, and is used by up to eight million people a day. The company said in 2014 that "the system is struggling to cope with the demands of 21st-century London".