NEW YORK—Safety regulators warned people with children and pets Saturday to immediately stop using a treadmill made by Peloton after one child died and others were injured. The U.S. Consumer Product Safety Commission said children and at least one pet were pulled, pinned and entrapped under the rear roller of the Tread+ treadmill, leading to fractures, scrapes and the death of one child. The safety commission said in a news release and in emails that it knows of 39 “incidents” with the treadmill, involving “multiple” or “dozens” of children, but it did not specify a number of children. It said the majority of the incidents resulted in injuries, including the one death. The commission posted a video on its YouTube page of a child being pulled under the treadmill. Of the 39 incidents, 23 involved children, according to New York-based Peloton Interactive Inc.; 15 included objects like medicine balls, and …