brake lights on 1997 seville do not work. why? on 1997 Cadillac Seville SLS

the brake light bar on my 1997 cadillac seville sls works , but the lower brake lights do not. What is wrong?

If they both went out at the same time , you probably have a broken wire in the trunk harness. Are all the other lights including tag lights working?If you have a voltmeter that may help you determine if it's a ground or power issue.