diff --git a/core/tests/Drupal/TestSite/Commands/TestSiteTearDownCommand.php b/core/tests/Drupal/TestSite/Commands/TestSiteTearDownCommand.php
index bbb635ed8c..e0019a047f 100644
--- a/core/tests/Drupal/TestSite/Commands/TestSiteTearDownCommand.php
+++ b/core/tests/Drupal/TestSite/Commands/TestSiteTearDownCommand.php
@@ -3,8 +3,6 @@
 namespace Drupal\TestSite\Commands;
 
 use Drupal\Core\Database\Database;
-use Drupal\Core\DrupalKernel;
-use Drupal\Core\Site\Settings;
 use Drupal\Core\Test\TestDatabase;
 use Drupal\Tests\BrowserTestBase;
 use Symfony\Component\Console\Command\Command;
@@ -76,10 +74,8 @@ protected function execute(InputInterface $input, OutputInterface $output) {
     $db_url = $input->getOption('db_url');
     putenv("SIMPLETEST_DB=$db_url");
 
-    $kernel = $this->bootstrapDrupal($test_database);
-
     // Handle the cleanup of the test site.
-    $this->tearDown($test_database, $db_url, $kernel->getAppRoot());
+    $this->tearDown($test_database, $db_url);
     $output->writeln("<info>Successfully uninstalled $db_prefix test site</info>");
   }
 
@@ -90,14 +86,13 @@ protected function execute(InputInterface $input, OutputInterface $output) {
    *   The test database object.
    * @param string $db_url
    *   The database URL.
-   * @param string $app_root
-   *   The app root.
    *
    * @see \Drupal\Tests\BrowserTestBase::cleanupEnvironment()
    */
-  protected function tearDown(TestDatabase $test_database, $db_url, $app_root) {
+  protected function tearDown(TestDatabase $test_database, $db_url) {
     // Connect to the test database.
-    $database = Database::convertDbUrlToConnectionInfo($db_url, $app_root);
+    $root = dirname(dirname(dirname(dirname(dirname(__DIR__)))));
+    $database = Database::convertDbUrlToConnectionInfo($db_url, $root);
     $database['prefix'] = ['default' => $test_database->getDatabasePrefix()];
     Database::addConnectionInfo(__CLASS__, 'default', $database);
 
@@ -107,30 +102,46 @@ protected function tearDown(TestDatabase $test_database, $db_url, $app_root) {
     array_walk($tables, [$schema, 'dropTable']);
 
     // Delete test site directory.
-    file_unmanaged_delete_recursive($test_database->getTestSitePath(), [BrowserTestBase::class, 'filePreDeleteCallback']);
+    $this->fileUnmanagedDeleteRecursive($test_database->getTestSitePath(), [BrowserTestBase::class, 'filePreDeleteCallback']);
   }
 
   /**
-   * Bootstraps the drupal kernel.
+   * Deletes all files and directories in the specified filepath recursively.
    *
-   * @param \Drupal\Core\Test\TestDatabase $test_database
-   *   The test database object.
+   * Note this version has no dependencies on Drupal core to ensure that the
+   * test site can be torn down even if something in the test site is broken.
+   *
+   * @param $path
+   *   A string containing either an URI or a file or directory path.
+   * @param callable $callback
+   *   (optional) Callback function to run on each file prior to deleting it and
+   *   on each directory prior to traversing it. For example, can be used to
+   *   modify permissions.
    *
-   * @return \Drupal\Core\DrupalKernel
-   *   The Drupal kernel.
+   * @return bool
+   *   TRUE for success or if path does not exist, FALSE in the event of an
+   *   error.
+   *
+   * @see file_unmanaged_delete_recursive()
    */
-  protected function bootstrapDrupal(TestDatabase $test_database) {
-    $kernel = new DrupalKernel($this->getApplication()->getName(), $this->autoloader, FALSE);
-    $kernel->setSitePath($test_database->getTestSitePath());
-    require_once $kernel->getAppRoot() . '/core/includes/bootstrap.inc';
-    drupal_valid_test_ua($test_database->getDatabasePrefix());
-
-    // Finish booting Drupal in order to use functions like
-    // file_unmanaged_delete_recursive().
-    Settings::initialize($kernel->getAppRoot(), $kernel->getSitePath(), $this->autoloader);
-    $kernel->boot();
-    $kernel->loadLegacyIncludes();
-    return $kernel;
+  protected function fileUnmanagedDeleteRecursive($path, $callback = NULL) {
+    if (isset($callback)) {
+      call_user_func($callback, $path);
+    }
+    if (is_dir($path)) {
+      $dir = dir($path);
+      while (($entry = $dir->read()) !== FALSE) {
+        if ($entry == '.' || $entry == '..') {
+          continue;
+        }
+        $entry_path = $path . '/' . $entry;
+        $this->fileUnmanagedDeleteRecursive($entry_path, $callback);
+      }
+      $dir->close();
+
+      return rmdir($path);
+    }
+    return unlink($path);
   }
 
 }
diff --git a/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php b/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php
index 4f764df60b..657dba615d 100644
--- a/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php
+++ b/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php
@@ -80,6 +80,10 @@ public function testInstallWithNonSetupClass() {
    * @coversNothing
    */
   public function testInstallScript() {
+    $simpletest_path = $this->root . DIRECTORY_SEPARATOR . 'sites' . DIRECTORY_SEPARATOR . 'simpletest';
+    if (!is_writable($simpletest_path)) {
+      $this->markTestSkipped("Requires the directory $simpletest_path to exist and be writable");
+    }
     $php_binary_finder = new PhpExecutableFinder();
     $php_inary_path = $php_binary_finder->find();
 
@@ -146,7 +150,10 @@ public function testInstallScript() {
     $test_file = $this->root . DIRECTORY_SEPARATOR . $test_database->getTestSitePath() . DIRECTORY_SEPARATOR . '.htkey';
     $this->assertFileExists($test_file);
 
-    // Tear down the other site installed.
+    // Tear down the other site installed. Tear down should work if the test
+    // site is broken. Prove this by removing its settings.php.
+    $test_site_settings = $this->root . DIRECTORY_SEPARATOR . $test_database->getTestSitePath() . DIRECTORY_SEPARATOR . 'settings.php';
+    $this->assertTrue(unlink($test_site_settings));
     $command_line = $php_inary_path . ' core/scripts/test-site.php tear-down ' . $other_db_prefix . ' --db_url "' . getenv('SIMPLETEST_DB') . '"';
     $process = new Process($command_line, $this->root);
     // Set the timeout to a value that allows debugging.
@@ -164,6 +171,10 @@ public function testInstallScript() {
    * @coversNothing
    */
   public function testInstallInDifferentLanguage() {
+    $simpletest_path = $this->root . DIRECTORY_SEPARATOR . 'sites' . DIRECTORY_SEPARATOR . 'simpletest';
+    if (!is_writable($simpletest_path)) {
+      $this->markTestSkipped("Requires the directory $simpletest_path to exist and be writable");
+    }
     $php_binary_finder = new PhpExecutableFinder();
     $php_binary_path = $php_binary_finder->find();