Sears, Roebuck and Co. promised to give Forrer permanent employment. Forrer sold his farm at a loss

Question:

Sears, Roebuck and Co. promised to give Forrer permanent employment. Forrer sold his farm at a loss to take the job. Shortly after beginning work, he was discharged by Sears, which claimed that the contract could be terminated at will. Forrer claimed that promissory estoppel prevented Sears from terminating the contract. Was he correct? [Forrer v Sears, Roebuck & Co., 153 NW2d 587 (Wis)]