Ten mountaineers, including a Texas woman, led by world-famous climber Nirmal Purja, are missing after an avalanche on Pakistan’s Broad Peak — and an experienced American alpinist familiar with the conditions told The Post he feared the mountain could become a death trap.

A snowslide struck the ten-person team as they trekked over the 26,400-foot peak in the Karakoram mountain range around midday Thursday, according to the Alpine Club of Pakistan.

Purja led the expedition consisting of Mallory Geis of Texas, Sohail Sakhi of Hunza, one Omani climber, one Chinese climber identified as “Mr. Wang,” one unidentified foreign climber, and five Nepalese mountaineers.

Purja, a former Royal Marine, is a 43-year-old Nepalese climber famous for ascending 14 of the world’s tallest mountains. His astonishing climbs were featured in the Netflix film “14 Peaks: Nothing is Impossible.”

Authorities have received no communication from the crew atop the world’s 12th tallest mountain and have mobilized an all-out search-and-rescue mission.

A high-altitude climber who led an expedition up Broad Peak last week told The Post Thursday he feared recent weathe conditions could spell trouble.

“It had been raining every day, which means that at high altitude, it would have been snowing,” said Napier Sandford Fuller, 53.

“I remember thinking, sh-t, they’re going to have a hell of a problem because if it’s raining … for a week straight, it’s going to have a huge snow load on that mountain,” added Fuller.

The dad of four is no stranger to dangers while climbing the same mountain.

He said he had a near-death experience on the mountain while leading the team under a contract with Seven Summit Treks, a Nepalese travel company that organizes expeditions on high-altitude peaks.

As he reached 26,000 feet up the summit ridge of Broad Peak, a fixed rope anchor snapped and sent him into a free fall — a “terrifying” incident he said was nearly fatal.

“Usually that would be fatal, but I was able to do what’s called self-arrest. You flip a few times and then just grab the snow and kick your feet in like a little freight train; you just stop,” he said.

After the distressing ordeal and concerns about the equipment’s quality on the mountain, Fuller and his sherpa decided not to scale the remaining vertical gap.

A picture taken by the climber captured Geis, a travel photographer based in San Antonio who is a member of the missing group, camped out on a mountain ridge.

Geis struggled with altitude sickness during an initial attempt to ascend Broad Peak — her first try at climbing a mountain of that monstrous height, Fuller said.

Fuller was Geis in her previous climb as they stopped at campsites to acclimate to the altitude.

Geis hesitated about going up the mountain a second time but was convinced by a local guide that she was strong enough to do it.

“Mallory, she’s a Texan, a real nice young lady, her first 8,000 [meter],” Fuller said. I was talking to her like she didn’t want to climb an 8,000 … and met this guy, the guide, he’s a local, and he convinced her that she was strong enough to climb an eight. But it’s not really her idea at all.”

The Alpine Club of Pakistan said in a statement that “every possible effort” was being made to secure helicopter support and that “all available resources are mobilized at the earliest opportunity.”

The Post has contacted the Alpine Club of Pakistan for further comment.