A member of the rock climbing community has been left with a broken arm and severed tendons after being hit by a rock on Tung Lung Chau, off Clearwater Bay peninsula. The climbing community think a hiker threw the rock from the cliff above, unaware there were people below.

The victim was sitting below the cliff, watching as others climbed when the rock struck his arm. He was airlifted from the island. He had the tendon reattached and plates inserted in the arm, but will need to wait to discover if there is lasting nerve damage.

Tung Lung Chau is a popular climbing spot. One area known as the Technical Wall has a wide sea platform that climbers sit on as their fellow rock enthusiasts scale the crags above, but occasionally they are showered by falling debris.

Stuart Millis, a prominent member of the climbing community who operates the website Hong Kong Climbing, said he and fellow climbers cleared loose rocks from above the crag, and hikers tend not to get close enough to the edge to accidentally knock a rock loose, suggesting the rock was thrown.

“There’s anger and frustration because it is irresponsible,” Millis said. “If you can see the sea you might be inclined to throw a rock and see it go ‘plop’. But doing it when you can’t see the bottom ...”

The rock that caused the damage. Hikers rarely get close enough to the edge to dislodge a rock, so climbers think it was thrown.

The rock was the “size of a brick”, Millis said, adding that if it had hit someone on the head it would have been “game over”.

Millis has emailed the Agriculture, Fisheries and Conservation Department (AFCD) and asked for a sign to be put up saying “beware, people below”. A similar request was made to the AFCD for Lion Rock a few years ago, Millis said, and they responded quickly, erecting a sign, so he is hopeful for the same again.

“We just want people to think about their actions,” he said. “It’s a beautiful spot, so we don’t want to stop people going there. We aren’t asking for big nets or anything like that.”

In Millis’ time climbing in Hong Kong, he has seen a few flurries of rocks come down Tung Lung’s crags, but rarely, if ever, has he seen a rock this big.

“In the last few years you’re getting more and more people who are heading out to nature,” he said. “So maybe there are more people who just aren’t aware.

“A sign at least warns people and makes them think twice,” Millis added.