Two months after the unprecedented incident in which millions of Windows computers were taken offline after a bug in the software update, the company’s chief executive is expected to give an explanation to the U.S. Congress today, Tuesday.

Adam Meyers, a top executive of CrowdStrike, will appear before the congressmen. He is expected to apologize for the error and stress his company’s determination to ensure it does not happen again.

The committee has also called CrowdStrike CEO George Kurtz, but for now he is not on the witness list.

As the BBC points out, the full extent of the problems from the July 19 blackout are only now beginning to emerge.

Because of the bug, there were problems treating patients, cancelled hospital appointments and surgeries, postponed airline flights around the world, and e-commerce applications. It is estimated that around 8.5 million computers around the world were affected.

The company blamed the problem on a “bug that went unnoticed” that reached users’ computers causing a plethora of problems.