school. the gun was found at the scene. witnesses say lane walked up to a group of students sitting in the cafeteria and opened fire. the latest polls put republican presidential frontrunners mitt romney and rick santorum in a dead heat going into today s primaries. both candidates have made a final push in michigan. the second contest is in arizona. michigan is a vital test of romney since he was born and raised there and his father served as governor. world business today starts now. good morning from cnn london. i m nina dell santos. good afternoon from cnn hong kong. i m andrew stevens. welcome to world business today. the top stories this tuesday, february 28th. asia chief explains the latest results and tells us where the growth is. the world conference, not his latest company s weapon against apple and google. it was wall street s gordon gecko who famously said greed is good. the actor who played him now has a very different message. first up, though,