Rails app redirects root request to /404 - ruby-on-rails

Question

I can't figure out why my application isn't working properly.
I've got the following routes.rb:
Rails.application.routes.draw do
root to: 'visitors#index'
# ... other routes
# Default root
get '*path', to: "error#error_404"
end
I enter the http://localhost:3000 in the browser url and get redirected to http://localhost:3000/404. Logs tell me one thing:
Started GET "/404" for 127.0.0.1 at 2015-08-31 14:24:50 +0300
Processing by ErrorController#error_404 as HTML
Parameters: {"path"=>"404"}
Rendered error/error_404.html.slim within layouts/application (0.8ms)
Rendered layouts/_navigation_links.html.slim (2.2ms)
Rendered layouts/_navigation.html.slim (3.2ms)
Rendered layouts/_messages.html.slim (0.1ms)
Rendered layouts/_footer.html.slim (0.1ms)
Completed 200 OK in 876ms (Views: 875.3ms | ActiveRecord: 0.0ms)
Other related files are the following:
visitors_controller.rb
class VisitorsController < ApplicationController
def index
#specializations = Specialization.order(name: :asc)
end
...
views/visitors/index.html.slim
- if #specializations.count == 0
h3.bg-primary.text-center = I18n.t('layout.no_specializations')
- #specializations.each_with_index do |specialization, index|
- if index % 3 == 0
.row
.col-sm-4
= link_to specialization
img src="#{specialization.avatar.url(:thumb)}" /
p.text-center
= specialization.name
- if index % 3 == 2
What can be the issue here?
P.S. When I enter e,g, localhost:3000/specializations/1 the resulting page gets normally loaded.
UPDATE
curl localhost:3000 gets the right HTML, without any redirection.

Answer 1

It turned out to be bad slim code. This line:
img src="#{specialization.avatar.url(:thumb)}" /
should be refactored into
img src=specialization.avatar.url(:thumb) /
Done. works.