Beginning my 60 mile drive home with my daughter and a tow truck driver.

At a red light, my 2005 S60 started making a grinding-type sound. Then a few seconds later it died, and wouldn't start again. A couple gentleman helped me push the car across the intersection to park, then I noticed the river of coolant flowing from my car down the gutter.

This car has been well-maintained, with a recent oil changed and a mechanic once-over while getting my front brakes replaced.

Any advice about what might be wrong?

Update: My water pump failed with zero warning, causing damage to the timing belt. All bad news. Wondering now if there's any way to determine whether more damage (besides the pump and belt) has occurred? Like warping of...things? Or does this require a trip to mechanic to find out?

 

These are "interference engines" so the most likely event is you have bent exhaust valves. Normally A compression test will tell you that, but with a broken timing belt you'd probably need an inspection camera via the spark plug hole. If you didn't overheat you probably don't have a warped head but a valve job is the likely outcome here. To do the compression test you'd need to install a new belt, set the VVT gear timing and then finally run the test (with a 90% probability there is a bent valve).