diff --git a/cloud/apps/sandbox-control/src/lifecycle.ts b/cloud/apps/sandbox-control/src/lifecycle.ts
index 7fa7463e73f..c35e0feb5ee 100644
--- a/cloud/apps/sandbox-control/src/lifecycle.ts
+++ b/cloud/apps/sandbox-control/src/lifecycle.ts
@@ -19,6 +19,7 @@ import type { Keyring } from './secrets-crypto'
 import { ORCAD_PORT, drainOrcad, runningOrcad, startOrcad, type OrcadReady } from './sandbox-vm-commands'
 import { claimPooledVm, deletePooledVm, maintainPool, type PoolConfig, type PooledVm } from './pool'
 import {
+  detachFromWorkspace,
   NO_SESSION,
   countActiveSandboxes,
   countActiveSandboxesForUser,
@@ -400,6 +401,9 @@ export async function createSandbox(
       // A pooled VM that will not take the session is discarded; the caller still gets a workspace.
       console.log(JSON.stringify({ event: 'pool_adopt_failed', error: String(error).slice(0, 200) }))
       await failAndRelease(deps, (await getSandbox(deps.db, row.id)) ?? row)
+      // Destroy can stop short (e.g. the provider's delete snapshot is still being written); the cron
+      // finishes it. That row never held user data, so it lets go of the workspace now.
+      await detachFromWorkspace(deps.db, row.id)
       return createSandbox(deps, caller, request, { pool: false })
     }
   }
diff --git a/cloud/apps/sandbox-control/src/store.ts b/cloud/apps/sandbox-control/src/store.ts
index a005736c857..2c41ccdcafa 100644
--- a/cloud/apps/sandbox-control/src/store.ts
+++ b/cloud/apps/sandbox-control/src/store.ts
@@ -98,6 +98,14 @@ export function getSandboxByProviderName(db: D1Database, name: string): Promise<
   return db.prepare('SELECT * FROM sandboxes WHERE provider_name = ?').bind(name).first<SandboxRow>()
 }
 
+/** A failed attempt that is still being cleaned up stops blocking its workspace (unique live index). */
+export async function detachFromWorkspace(db: D1Database, id: string): Promise<void> {
+  await db
+    .prepare(`UPDATE sandboxes SET workspace_id = workspace_id || '#abandoned:' || id WHERE id = ? AND status <> 'destroyed'`)
+    .bind(id)
+    .run()
+}
+
 export function liveSandboxForWorkspace(
   db: D1Database,
   accountId: string,
diff --git a/cloud/apps/sandbox-control/test/pool.test.ts b/cloud/apps/sandbox-control/test/pool.test.ts
index 871b33f2c90..2f0524ca2d6 100644
--- a/cloud/apps/sandbox-control/test/pool.test.ts
+++ b/cloud/apps/sandbox-control/test/pool.test.ts
@@ -75,6 +75,39 @@ describe('warm pool', () => {
     expect(h.vercel.boxes.get(`orca-test-${res.body.sandbox.id}`)!.params.tags.orcaPool).toBeUndefined()
   })
 
+  it('a failed adopt whose cleanup stops short still gives the caller a fresh VM (no sandbox_destroying conflict)', async () => {
+    const { h, deps, poolRows } = await pooledHarness('1')
+    await maintainPool(deps())
+    const pooledId = poolRows()[0]!.id as string
+    const pooledName = `orca-test-${pooledId}`
+    const realPolicy = h.vercel.updateNetworkPolicy.bind(h.vercel)
+    h.vercel.updateNetworkPolicy = async (sessionId, policy) => {
+      if (sessionId === h.vercel.boxes.get(pooledName)?.sessionId) {
+        throw new Error('policy update failed')
+      }
+      return realPolicy(sessionId, policy)
+    }
+    // The pooled VM's delete leaves a snapshot that will not delete yet: destroy stops at 'destroying'.
+    const realDeleteSnapshot = h.vercel.deleteSnapshot.bind(h.vercel)
+    h.vercel.deleteSnapshot = async (id) => {
+      if (h.vercel.snapshots.get(id)?.sandboxName === pooledName) {
+        throw new Error('snapshot still being written')
+      }
+      return realDeleteSnapshot(id)
+    }
+    const res = await h.call('POST', '/v1/sandboxes', { body: create })
+    expect(res.status).toBe(200)
+    expect(res.body.sandbox.id).not.toBe(pooledId)
+    const abandoned = h.raw.prepare('SELECT status, workspace_id FROM sandboxes WHERE id = ?').get(pooledId) as { status: string; workspace_id: string }
+    expect(abandoned.status).not.toBe('destroyed')
+    expect(abandoned.workspace_id).toBe(`ws-1#abandoned:${pooledId}`)
+    // The cron finishes the abandoned row once the provider lets go.
+    h.vercel.deleteSnapshot = realDeleteSnapshot
+    h.advance(30 * MIN)
+    await h.reconcile()
+    expect((h.raw.prepare('SELECT status FROM sandboxes WHERE id = ?').get(pooledId) as { status: string }).status).toBe('destroyed')
+  })
+
   it('skips the pool for sizes and regions it does not hold', async () => {
     const { h, deps, poolRows } = await pooledHarness('1')
     await maintainPool(deps())