Did you get this fixed yet? If not, which engine does it have, the 3.8L or 3.5L? You didn't run it out of gas, did you? If not, then verify that the engine has a fueling problem or not by spraying t-body cleaner into a vacuum hose, then immediately crank over the engine and see if it runs for a few seconds. If so, then the fuel pump probably failed.
IF it still doesn't start, does the tachometer move while cranking over the engine? If not, then probably safe to say the crankshaft sensor has failed. If the tach is moving, then pull a few of the spark plugs and see if any are wet. If so, make sure the wetness is only fuel, not coolant. If you suspect coolant and you have the 3.8L engine, then the upper intake manifold make have cracked along a cooling passage, causing coolant to get sucked into the engine. This is a somewhat common issue w/ that engine. Update this post if you can.