Drupal 7 Hook, if another module deletes a block

I've written a Drupal 7 module that adds about ten fields to the Block Administrator configuration form and stores the values ​​for those fields in a separate database table.
My module does not build blocks, but extends the functionality of a block, no matter which module it created.
I would like my module to delete the data in its own table when a module deletes a block from the list. "block" Table.
Is there a hook or other "universal" method to know when a block was deleted?

There does not seem to be one hook_block_deletealthough there is hook_node_delete. hook_entity_delete. hook_taxonomy_vocabulary_delete, etc.
I've looked at development guides to build blocks for some clues, but none of them found any examples of how they should be deleted.
I also looked at the source code of modules that create / delete blocks, such as: For example, I can not tell you how or if they send a notification that they have deleted a block.