The water pump is driven by the timing belt, when the water pump went, so does the timing belt. And without the timing belt, the engine won't run. Depending on mileage, might consider replace tensioner bearing and idler bearing too, not to mention the seals for the oil pump and the cam shaft.

N.E.O.

 

No oil on the dipstick does not bring any water pump maladies to mind. I think you're going to find that you have at least two problems. When was the last time that you checked your oil (and presumably found that it was OK)? How many miles on the car.

Water and oil will both deteriorate the timing belt. The car not starting might be a related issue here. However, I believe even in a 99 (no distributor right?), if the car even "stumbled" then the belt must still be intact. Maybe it slipped due to the lubricating effect of the coolant, but that is a stretch.

You're going to have to remove the timing belt to replace the water pump anyway so all of that should be readjusted when you put it back together. ^+1 with NEO on replacing any bad parts that you find in there when you open it up. For all the trouble that you go through to open it up and buckle it back together replacing those items is often considered good preventative maintenance.\

BTW, running an engine with a coolant leak is not particularly good for it. The engine cooling system is designed to have pressure to get the coolant where it needs to go (among other things). If there is a loss of pressure (a leak) even if you keep it topped off it doesn't work as efficiently. I would encourage you to try and fix it soon. It may be too late in that you mentioned that it is leaking "dirty" coolant. If that is oil you may have a leaking head gasket. (Hence the loss of oil in the pan.). Keep close track of both.

Kep

 

most of mystery solved...

I got it towed to a mechanic (thank you, AAA)

The water pump had a massive failure and the timing belt had definitely slipped & was to the point that it was keeping the car from running. I don't know if one caused the other, vice versa, or it was a coincidence.

The missing oil is still a mystery, but there's no oil spots at home or at work. Since I checked the level a few weeks ago and it was fine, I'm assuming that the loss occurred at roughly the same time as the other problems. The mechanic is going to check and replace any gaskets/seals that may have caused oil loss in that area before he puts the new timing belt on.

Hopefully there's not also a head gasket issue, but I guess that will become apparent after the water pump and belts have been replaced.

For now it looks like I'm going to get off relatively easy (but still not cheap) with a new water pump and timing belt.

I'd attempt a DIY, but it's my wife's car and I don't need to be in line for that kind of grief if something goes awry. ;-)

btw, it has 148k miles on it and this is the 2nd time the water pump has failed in spectaular fashion. The timing belt was replaced the first time as well because it was about due anyway.

Thanks for your insight and tips. I'll post back if anything else crops up during the repair.