The passenger steamer Princess Alice sank in the River Thames on the evening of 3 September 1878 after colliding with the much larger Bywell Castle near Woolwich. Around 650 people died in what remains the worst single loss of life in a Thames shipping disaster.

Princess Alice was a paddle steamer used for excursions from London towards Gravesend and Sheerness. Many aboard that day were families and other day-trippers who had visited Rosherville Gardens at Gravesend and were returning to London.

At about 7.40 p.m., Princess Alice was travelling through Gallions Reach near Woolwich when she encountered Bywell Castle, a large cargo steamship. The vessels collided, and Princess Alice was struck with enough force to split her hull. She sank within minutes.

Passengers were trapped inside the vessel or thrown into the Thames. Boats from Bywell Castle and other craft attempted to rescue them, but hundreds drowned.

The river’s condition made matters worse. Large quantities of untreated sewage from London’s sewer system were discharged into the Thames from nearby outfalls. Passengers struggling in the water therefore found themselves in a heavily polluted stretch of the river.

The precise death toll has never been established. Passenger vessels were not required to maintain a complete list of those aboard, and estimates vary. Around 650 deaths is generally accepted.

Bodies were recovered along the river during the following days, with temporary mortuaries established so relatives could identify the dead. Some victims were never identified.

A coroner’s inquest and a separate Board of Trade inquiry reached different conclusions about responsibility for the collision, making it difficult to assign blame.

The Princess Alice disaster exposed serious problems involving navigation, passenger safety and traffic on the increasingly busy Thames. No later single accident on the river has exceeded its death toll.