both low beams went out at the same time

I have a 1998 F150 Lariat with 74000 miles and the Triton V8. Both of the low beams just stoped working. The high beams work fine. The parking lights turn on manually and also with the auto control. I pulled all of the fuses, in dash and under hood that referred to headlamps. They all seem to be good. Nothing else electrical is affected. Don't think it is possible that both lights could burn out simultaneously. Any suggestions? Thanks.