Two major retailers say they will no longer sell e-cigarettes in the U.S. amid mounting health questions surrounding vaping. Supermarket chain Kroger and drugstore chain Walgreens announced Monday they would discontinue sales of e-cigarettes at their stores nationwide, citing an uncertain regulatory environment. The vaping industry has come under scrutiny after hundreds of people have fallen ill and at least eight have died after using vaping devices. Walmart announced last month that it would stop selling e-cigarettes at its stores nationwide.