My 2000 Sienna wouldn't start today. It just made a whirring noise when I turned the key. I figured it was the battery since it was a cheap two-year free warranty battery and it was two-and-a-half year old battery now. I had to get a jump start from the neighbor, but not until we realized my jumper cables were no good. I noticed there was no sparking when attaching to the battery terminals and that clued me into why it wasn't getting enough juice to start the van. The neighbor went and got his and after charging my battery for a few minutes I was able to get going.
My old jumper cables are in the trash now and new ones have replaced them. Don't let your emergency tools be worthless when you need them. Check your spare's air pressure, your flashlight's batteries, your jack's operation, and your jumper cable's conductivity. I was lucky that I was still home and not stranded somewhere with my kid.