Programmatically delete a field collection items

function _delete_node_fc_items($node, $field_name) {
  $fc_items = field_get_items('node', $node, $field_name);
  if (!isset($fc_items[0]))
    return;

  foreach ($fc_items as $fc_item) {
    entity_delete_multiple('field_collection_item', array($fc_item['value']));
  }

  $node->{$field_name} = array();
  node_object_prepare($node);
  node_save($node);
}