Elm checkbox checked bug

Main.elm

import Html exposing (..)
import Html.App as App
import Html.Attributes exposing (..)
import Html.Events exposing (onClick)


main =
  App.beginnerProgram { model = model, view = view, update = update }


-- MODEL

type alias Model = List String

model : Model
model =
  [ "one", "two", "three", "four" ]


-- UPDATE

type Msg = Kill String

update : Msg -> Model -> Model
update msg model =
  case msg of
    Kill name ->
      List.filter (\s -> s /= name) model



-- VIEW

viewLi : String -> Html Msg
viewLi s =
  li []
    [ input [type' "checkbox", onClick (Kill s)] [], text s ]


view : Model -> Html Msg
view model =
  ul [] (List.map viewLi model)