SonataAdminBundle/Resources/views/CRUD/list__action_delete.html.twig

<a href="{{ admin.generateUrl('delete', {'id': object.id}) }}" class="delete_link" title="{% trans from 'SonataAdminBundle' %}action_delete{% endtrans %}">
    <img src="{{ asset('bundles/sonataadmin/famfamfam/delete.png') }}" alt="{% trans from 'SonataAdminBundle' %}action_delete{% endtrans %}" />
</a>