It was knock-off time. Turning around at the top of the steps to the chemical storage, she came face-to-face with the killer. He knew exactly what he was doing. Giving her a strong hard push down the steps, she fell backwards and cracked her head so hard on the cement that she was out like a light before she knew it. It wouldn't be until the next morning before her colleagues found her bloodied body.
Unfortunately, the security camera failed to capture the killer as he had deliberately stayed out of the camera frame.