The Conrail engineer and brakeman were found to have been using marijuana.

Mr. Gates had been a Conrail engineer for almost 11 years.

The Conrail engineer had been smoking marijuana, which caused him to miss numerous warning signals.

In the test today, safety investigators first determined at what point along the track the Conrail engineer could have first seen the home signal.

More details were also provided about tests conducted Monday to determine if the Conrail engineer could have taken action to avoid the collision.

Two signals that should have warned a Conrail engineer away from the crash were tested immediately after.

As a Conrail engineer for 20 years, I have an interest in improving the lives of my fellow workers and those who will follow.

Quickly, the investigation focused on these questions: Were the signals that should have told the Conrail engineer to slow down, and then to stop, working?

Results of tests on the Conrail engineer and brakeman conducted shortly after the accident, are not yet available.

Investigators found that a cab whistle designed to warn the Conrail engineer to reduce speed had been taped over so it could not be heard.