On approaching it, the dead streets suddenly came alive, as if the entire energy of the city had been focused on one point. Barricades made from burning tires separated the police from groups of young men, exchanging rocks for gunfire.
The clashes had followed the funeral of more protesters, killed the day after the violence outside the prison.
"There are some injuries here," a member of the Red Crescent said as he sheltered from the gunfire in a side street. Ambulances flew by, their sirens blaring.
"We've seen gun bullets from the government. In four days we have seen more than 450 [injured]."
The prospects of a hastily arranged march to defy Morsy's curfew, looked bleak.
But at 8.30pm a crowd of thousands gathered near the same spot the Red Crescent had been waiting to ferry the injured to hospital. They marched through the smoldering barricades towards where the gunfire had previously come from.
Now the army, not the police, was in charge.
Armored personnel carriers and armed troops were stationed on street corners and outside important military and civilian buildings.
At its core were the fans of Al Masry ultras group the Green Eagles. But they were by no means alone. The marchers had come from all sections of Port Said. Several hundred women marched together, denouncing Morsy and Cairo.
The curfew came and went, the crowd mocking its passing. "It's 9 o'clock!" they chanted as they passed the stationed troops.
But there was no animosity towards the army. The police was the enemy. Protesters took it in turns to hug and kiss the young soldiers.
Few would readily admit to being Al Masry fans, nor say whether they were there on that fateful night almost a year ago that set in motion this chain of deadly events.
What they would say is that they believed a miscarriage of justice had taken place, that Morsy had sacrificed Port Said to prevent chaos in Cairo, that traditional antipathy towards Port Said was at play.
"People are truly sure that these people [the 21 sentenced to death] didn't kill anyone. We didn't do it and they [the Ahlawy] don't believe we didn't do this," said Tariq Youssef, a 32-year-old accountant, who was on the march with a friend.
"Al Masry will not be back for five years. I'm a big Masry fan. But I can't go anywhere. All the supporters for the big teams in Cairo or anywhere believe that Al Masry supporters did this."
For Tariq, admitting to being an Al Masry supporter outside of Port Said was impossible.
"They say: 'You killed them the Ahly supporters. You are like a terrorist.' Nobody believes us we didn't do anything here. There will be no football in the next five years."
As the march moved back towards the place it had started, machine gun fire rang out once again.
This time it was all around the march, front and back. The crowd scattered. A protester had been shot dead at the back of the march, next to the Al Arab police station.
"In three days we have lost 21 people, judged to be executed, and also about 39 murdered and many injured so there is no family which have not lost a friend, a colleague, a neighbour.
"You can consider this a sort of vendetta between the people and the police," said Muhammad el Agiery, an English tutor who had stayed until the end.
"People are going to stay out all of the night, every day for a month. They reject and refuse the curfew imposed by Morsy," he added.
The next morning the storm was gone and the sun was shining. But the cycle of violence continues. Another funeral march will begin, another barricade will likely be set on fire, and another curfew broken.