CBC is reporting that Electro-Motive Diesel has locked out its workers from the London, Ontario plant. The unionized workers (from the Canadian Auto Workers) were negotiating with the company, when the company made a "final" offer of a 50% pay cut (from $35 to $16.50/hour).
EMD is owned by Caterpillar, Inc. through Progress Rail. EMD used to be owned by General Motors, but was sold to private investors in 2005. Caterpillar purchased EMD in the summer of 2010.
It is speculated that Caterpillar is interested in moving its locomotive production operation to the USA. The London plant performs final assembly of all EMD locomotives.
EDIT: Updated CBC story