Galen Stoller was killed at a railroad crossing when an AMTRAK train hit his car. The crossing was marked with a stop sign and a railroad-crossing symbol, but there were no flashing lights. Galen’s parents filed a suit against National Railroad Passenger Corp. (AMTRAK) and Burlington Northern & Santa Fe Railroad Corp., alleging negligence in the design and maintenance of the crossing. The defendants argued that Galen had not stopped at the stop sign. Was AMTRAK negligent? What was the proximate cause of the accident? Discuss.