Cooper Union, which has offered a top engineering and architecture education without charging anyone tuition for more than a century, may have to start charging tuition, The New York Times reported. The institution has made no decision on tuition, and officials have said that any tuition plan would not affect low-income students. Financial difficulties have raised the need to charge, Cooper Union leaders say. Many alumni and students are furious about the potential end of a tradition that they see as central to Cooper Union. Students are planning to walk out of classes Wednesday as part of a protest. A petition to preserve free tuition has attracted more than 2,000 signatures.