Nathan Fitzgerald was a 27-year-old schoolteacher who played Australian rules football for a local team in Melbourne. On Friday, he was in a match when he collided with an opponent. Three days later, on Monday, he died at Royal Melbourne Hospital The Guardian. He had recently gotten engaged news.com.au.

What happened during the match is now drawing attention far beyond the local club. Witnesses say Fitzgerald hit his head three times. First, he clashed heads with an opposing player while making a tackle. Then, as he fell, he hit his head again. Finally, his head struck the ground — but not just grass. The oval had a synthetic layer (made to handle wear), and underneath that was concrete The Guardian.

Doctors and sports safety experts say concrete underneath a sports field is dangerous. Dr Alan Pearce, who studies head injuries in sports, explained it this way: concrete does not absorb the force of impact the way grass or soil does. It's like the difference between falling on a bed and hitting concrete — one has give, one does not. Annitta Siliato, who runs the Concussion Legacy Foundation Australia, said these pitches are "totally unsafe" and should be removed from community grounds.

Why does a football field have concrete underneath? The answer goes back to the 1800s. Australian rules football was invented by cricket club members who wanted to keep players fit during the off-season. So they used cricket fields for football in winter. The problem: cricket fields need concrete underneath for a durable wicket (the playing surface in cricket). Now, more than a hundred years later, many community ovals still have this same setup. Concrete meant for cricket sits under fields where football players fall and collide at high speed.

Here is what worries safety experts: a thin synthetic layer on top cannot stop the force of a human head hitting concrete underneath. When someone falls on grass, the ground gives way a little, spreading out the impact. Concrete does not give way — it sends all the force straight up into a person's head.

Memorials and tributes have begun. Football clubs across Australia will wear black armbands this weekend in honour of Fitzgerald. Sports commentators have spoken about the loss of a teacher and a devoted player ABC News.

So far, no official investigation has been announced by the major football organisations or local government. But the question now facing sports leaders is clear: if 16 community ovals in just one area of Melbourne have concrete underneath, how many more exist across the country? And should concrete-based pitches be removed from places where people play contact sports?