Tributes have been paid to the two teenagers, with Tonibeth, from Barmston, Washington, being hailed as a hero.
Friends of the pair have been laying flowers on the riverbank and paying their respects.
Amy Bell, 13, said: "I knew Chloe, she was a fantastic girl and she did not deserve this at all."
Joss Richards, 13, who was in the same school class as Tonibeth, said: "I'm really devastated that she has gone."
One card left with flowers said: "RIP Tonibeth you are a hero."
Another left for Chloe said: "Heaven has gained a beautiful angel who will be greatly missed."