Federal regulators warned parents on Friday that a popular infant seat can be deadly. At least 10 infants have died since 2015 when they rolled from their back to their stomach or side while unrestrained in the Fisher-Price Rock ‘n Play, according to the Consumer Product Safety Commission. As a result, the agency is recommending that the sleeper not be used as soon as a baby can roll over or after 3 months of age. Parents have already been told not to use the seat without the three-point harness, but the CPSC said the deaths show that not everyone is heeding the advice. Fisher-Price joined in the warning but noted that the Rock ‘n Play meets safety standards.