CrowdStrike (CRWD.US) fell nearly 10% after Delta Air Lines (DAL.US) filed a lawsuit.

On Tuesday, CrowdStrike (CRWD.US) shares fell, down nearly 10% to $233.34 at the time of writing, after it was reported that Delta Air Lines (DAL.US) had hired David Boies, a prominent lawyer, to sue CrowdStrike and Microsoft (MSFT.US) for damages.

CrowdStrike had previously caused a widespread blue screen of death bug that affected about 85 million Windows computers, disrupting the normal operation of industries including aviation, banking and healthcare. The bug had a particularly severe impact on airlines, with Delta Air Lines being one of the biggest victims.

It is estimated that the bug has caused Delta Air Lines $350-500 million in damages. After cancelling nearly 7,000 flights, Delta Air Lines is currently dealing with over 176,000 requests for refunds or compensation.