A co-worker experienced this after driving 40 miles to work. Car stalled and will not start. Turns over fine but no start. Any thoughts as to what may cause this? Thanks in advance.

You sure don't say much to go on, got gas in the tank? Could be many things.
As other posters suggest check that cam is turning and check for diagnostic codes. After that another basic diagnostic step is to determine if you are missing spark or fuel. Both are needed to start the engine. Does the tach nudge up slightly while attempting to start? If yes then you probably have spark if not then you would look towards a fuel problem.

could be rpm sensor, could be a lot of things.

Pop the hood and use the IDU to get the codes that were set.

Read the FAQ to see how to use the IDU and interpret them, c'mon back to the Board!

first thing that comes to mind it the timing belt. if the car sounds like it cranks normally,(sounds like it has compression on all 4 cylinders at even intervals) then u can rule this out...or just take off the oil cap and have someone crank it while u look inside. if the cam turnes you can usually rule that out.
Mark