Libya conflict: Smoke and explosions mark Sirte battle
It was the thick black smoke which signalled an assault on Sirte city centre - the green Gaddafi flags clearly still flying high over the outskirts.
They said a Nato bomb had struck pro-Gaddafi positions, but we did not see or hear it as the first battle got under way to take a well-defended gate.
We arrived as troops loyal to the National Transitional Council had taken control of it and rushed forward, trying to pull a string of green flags from a lamp post.
They fired at the rope in an effort to break it as bullets ricocheted off the metal, but then all pulled at the rope together as the flags fluttered onto the road to be ripped and torn.
A hail of celebratory gunfire marked the moment they had reached Col Gaddafi's birthplace - they have fought every mile of Libya's long coast road from Benghazi to reach here.
For weeks they have advanced west, steadily breaking through defensive line after defensive line across the road in the desert, next to the sea.
But there was not long for them to enjoy the moment - as the pro-Gaddafi troops reorganised themselves and bullets started flying.
We raced back up the road to behind a concrete water tower where we watched the battle for the city proper to begin.
The roar and flash of rockets crashed across town as the fighting moved onto the streets.
The staccato tear of machine gun fire was broken by the crunch of incoming rockets and mortar bombs.
Bullets whistled overhead as a group of NTC fighters edged along a wall before firing grenades and machine guns in the general direction of the city centre - into its impressive buildings and new construction sites.
We had met many civilians escaping Sirte earlier in the day - the city centre is now incredibly dangerous for those unable to get away from the fighting.
Their faces told a story of fear - they had been short of food, water and electricity they told us - scared of what might happen if they stayed, or if they left.
A woman looked out at the soldiers from the back seat of a saloon car, clearly terrified.
They said they were told the rebels would kill them, slit their throats; but instead they were welcomed with water and fuel for their cars.
Hundreds have made it out over the past few days as the NTC troops advanced.
One had a lucky escape - his car had a twisted metal scar after being hit by a bullet.
"People in Sirte are waiting for you, they have been waiting since February 17th," he said.
"Sirte will welcome you. It's open, take it."
As the sun set the firing continued - artillery shells from the south, more troops entering in the west, constant fighting in the east.
Armed pick-up trucks gathered behind walls and behind piles of earth, continuing to fire as the wind from the sea whipped up the sand and the rocket smoke to create an eerie, hazy orange light.
Snipers will move around at night, positions will be dug in ready for daybreak as the once rag-tag rebels battle for one of the few remaining Gaddafi strongholds.
It is a hugely symbolic prize in their bid to control the whole country.
How long the battle lasts depends on the determination of those defending Sirte, and their appetite to fight for it street-by-street.