American Cyanamid Co. (defendant) leased a railroad car to ship 20,000 gallons of acrylonitrile, a highly toxic and flammable chemical. Missouri Pacific Railroad handled the car and directed it to a yard outside of Chicago owned by Indiana Harbor Belt R.R. (plaintiff). When the car arrived, Indiana’s employees noticed it was leaking. Approximately one-quarter of the chemical had leaked out. The Illinois Department of Environmental Protection ordered decontamination measures that cost Indiana nearly $1 million. Indiana sued Cyanamid to recover the costs. Indiana argued that Cyanamid had negligently maintained the shipping car and was strictly liable because shipping acrylonitrile through Chicago was an abnormally dangerous activity. The district court granted Indiana summary judgment on its strict liability claim and dismissed Indiana's negligence claim. Cyanamid appealed and Indiana cross-appealed.