Here are the main four questions that are regularly asked about the incident.
Why did Egyptian authorities lift a three-year crowd ban in the Premier League despite lingering security concerns?
Egyptian sports media have long called for the return of fans to the stands, complaining that their absence deprive the league games of any passionate atmospheres, with dour matches taking place behind closed doors.
Egypt's authorities, particularly the interior ministry, repeatedly said they were more focused on maintaining order in the turmoil-stricken country rather than securing football matches.
But a continental game for Cairo giants Ahly last December marked a turning point in that debate, with the team's hardcore supporters (Ultras Ahlawy) earning widespread and rare acclaim for their ruly behavior during the game as Ahly won the CAF Confederation Cup for the first time
Egyptian President Abdel-Fattah El-Sisi, in another surprise move, lavished praised on Ultras Ahlawy and a rapprochement between the state and the hardcore fan groups seemed well on the cards.
The authorities eventually decided to gradually lift the crowd ban, saying that up to 10,000 spectators will be allowed to attend league matches in the second half of the season but left it up to the hosting team to decide whether to play behind closed doors or before fans.
What exactly happened in Zamalek's match against ENPPI?
Although on paper 10,000 fans were allowed to attend the match at the army-owned Air Defence Stadium in Cairo, the mechanism of distributing tickets made it difficult for many to go through the proper legal channels.
Outspoken Zamalek chairman Mortada Mansour, a bitter enemy of the club's main fan group (Ultras White Knights), said 5,000 tickets would be distributed by the club itself and as many would be put up for public sale.
The scarcity of tickets saw thousands of supporters crammed in a makeshift and narrow, barbed wire pathway erected by security forces in front of a tiny stadium gate, prompting many fans to shout and urge security forces to let them out.
Many of them hoped they would sneak in or at least obtain a ticket from the black market, according to eyewitnesses, but riot police reacted quicker than expected, firing tear gas to disperse them.
But there was no way out.
In trying to escape in a very narrow passage, 19 were either killed in a stampede or suffocated because of teargas inhalation in another shocking incident, three years after Egypt's worst-ever football tragedy left over 70 Ahly fans killed in coastal city Port Said.
A 14-year-old girl died on Tuesday at a Cairo hospital, becoming the Cairo football tragedy's 20th victim.
What are the immediate consequences of the Cairo football disaster?
The Egyptian Premier League, which was cancelled twice in the past three seasons, was suspended for an indefinite period amid doubts over whether it could be resumed.
Zamalek's full-back Omar Gaber, a fan favourite who is known for his support of ultras groups, was also banned by the club after declining to take part in the game against ENPPI.
Egyptian police have arrested 21 Zamalek fans in the wake of the disaster, with reports saying they would be charged with attacking policemen, damaging police cars and terrorizing the public.
What do we expect in the coming period?
Ultras White Knights have vowed to avenge the deaths of the Zamalek supporters although they did not specify their next step.
"The truth is clear to the world and we know the criminals who incited the murder," UWK said in a statement on Facebook.
“We have passed through your courts many times, with no truth held up nor retribution for the wronged. The time has come for you to pass through our courts. What goes around comes around."
The Egyptian Football Association board said it would convene later this week to discuss the possibility of resuming the ill-fated competition.
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