1997 Nissan Altima died while driving

First have the charging system tested (battery and alternator). Most parts shops can do this for free, or pay a nominal fee to have it done by a mechanic. Check the overall condition of the battery cables. Check the battery hold down is keeping battery securely in place. Frayed ends and loose or corroded connections can kill power easily, especially when you are driving and things can move around. Trace those battery cables to their end points, such as the starter, starter relay, alternator, and chassis and engine grounds. Open the fuse box and check for loose fuses. Basically on an older vehicle like yours you have to look for wear and tear on those wiring harnesses.