No one sees the second train coming.
When I was in second grade, the sister of a classmate was killed by a train. She was waiting patiently at the crossing while the train passed. When it cleared the crossing she hopped on her bike and pedaled across.
Unfortunately, she didn't see or hear the second train coming from the opposite direction on the second set of tracks. She was killed instantly.
We all see the first train. But how many of us are looking out for the second?