By Paul Donnelley for MailOnline Families who lost loved ones in the Marchioness pleasure boat tragedy will attend a memorial service this week to mark the 25th anniversary of the Thames disaster, which claimed 51 lives. On August 20, 1989 - a hot, late-summer evening - the riverboat Marchioness, packed with  partygoers, collided with the dredger Bowbelle near Cannon Street Railway Bridge and sank in the Thames. There were 131 people on Marchioness crewing, waiting and attending a private birthday party; fifty-one of them drowned. The names of the dead, including Francesca Dallaglio, 19, the sister of former England rugby captain Lawrence Dallaglio, will be read out at the service on at Southwark Cathedral in south London on Wednesday.
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Pleasure boat Marchioness collided with dredger Bowbelle causing deaths of 51 partygoers
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Both vessels failed to keep a proper lookout on the night of the tragedy
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Tragedy occurred during birthday party for financier Antonio de Vasconcellos, 26 - who was one of those who drowned
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Coroner criticised for cutting the hands of the victims for ID purposes
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Names of dead will be read out at Southwark Cathedral service this week
The skipper of @placeholder Stephen Faldo was among the dead.