Error when deleting parent entry in structure section when child depth > 1

Description

SQL error issued when trying to delete entries that have structure based children with a depth greater than 1. When selecting entries with a depth < 2 deleting works without issue. Individual entries can be deleted fine too.

The data in the structure was imported with Feed Me (version below).

Steps to reproduce

Select a parent entry to delete within a structure section with a child depth of at least 2.

i.e. this:

[*] parent
    -> child level 1
        -> child level 2

and not this:

[*] parent
    -> child level 1

The resulting AJAX request produces an error:

{"error":"SQLSTATE[22003]: Numeric value out of range: 1690 BIGINT UNSIGNED value is out of range in '(`[dbname]`.`structureelements`.`level` - 2)'\nThe SQL being executed was: UPDATE `structureelements` SET `level`=`level`-2, `dateUpdated`='2019-07-01 15:35:18' WHERE ((`lft` >= 4102) AND (`rgt` <= 4103)) AND (`root`=698)"}

Additional info

• Craft version: 3.1.32.1
• PHP version: 7.2.19
• Database driver & version: MySQL 5.7.26
• Plugins & versions:
  AsyncQueue 2.0.0
  CP Field Inspect 1.0.5
  Dumper 2.0.0
  Feed Me 4.1.0
  Imager v2.1.10
  Queue Manager 1.1.0
  Redactor 2.3.3.2
  Redirect plugin for Craft 3 1.0.23
  Tags 1.0.5
  Template Select 2.0.2

Start by reproducing the deletion from the issue using a structure with a parent and two child levels, then inspect the SQL generated by the AJAX request. Done means deleting the parent succeeds without the BIGINT UNSIGNED error while deletion of shallower structures continues to work.