won't start - no warning prev.

Hi,
I own a '99 Chevy Blazer, 4.3L Engine.
I drove the car this weekend about 500 miles. No problems at all. Once,
two days ago, when I tried to start it, it didn't start from first try,
but I thought I didn't crank it long enough, and from the second try
started right away.

Last night, I parked my car, as normal. No lights on the panel, no
"check engine". All in good and normal working conditions.

Today in the morning, I got in the car to go to work... and when I
wanted to start it, is just rotating the engine (the battery is fine)
but the car doesn't start. Is not even trying to start, like there is no
gas in the engine and is not getting gas at all - not one firing.

While I was writing this post, I remembered that last night, just before
I got home I stopped to the gas station to get gas, I was running on low
fuel warning for few miles (15-20), but I didn't run out of fuel! I
filled up and went home (about 1 mile from the gas station).

What can be the problem?
Any ideas on what to try before calling a towing truck to take it to the
mechanic?

TIA,
-ioan