Elon Musk Twitter
Now playing
01:33
Watch: Musk tests small rescue pod
CHIANG RAI, THAILAND - JULY 18:  Twelve boys and their coach from the "Wild Boars" soccer team arrive for a press conference for the first time since they were rescued from a cave in northern Thailand last week, on July 18, 2018 in Chiang Rai, Thailand. The 12 boys, aged 11 to 16, and their 25-year-old coach were discharged early from Chiang Rai Prachanukroh hospital after a speedy recovery and thanked those involved in their rescue. (Photo by Linh Pham/Getty Images)
Linh Pham/Getty Images
CHIANG RAI, THAILAND - JULY 18: Twelve boys and their coach from the "Wild Boars" soccer team arrive for a press conference for the first time since they were rescued from a cave in northern Thailand last week, on July 18, 2018 in Chiang Rai, Thailand. The 12 boys, aged 11 to 16, and their 25-year-old coach were discharged early from Chiang Rai Prachanukroh hospital after a speedy recovery and thanked those involved in their rescue. (Photo by Linh Pham/Getty Images)
Now playing
02:05
Thai cave rescue: 'I told them, don't lose hope.'
Some of the boys who were trapped in a cave in Northern Thailand outside a hospital in Chiang Rai after being discharged.
Rebecca Wright/CNN
Some of the boys who were trapped in a cave in Northern Thailand outside a hospital in Chiang Rai after being discharged.
Now playing
00:58
See moment Thai boys get released from hospital
Thai Navy Seals
Now playing
01:26
Video shows Thai boys' rescue from cave
mckenzie inside thai cave
CNN
mckenzie inside thai cave
Now playing
01:28
CNN reporter goes inside Thai cave
Vern Unsworth, British cave diver
Rebecca Wright/CNN
Vern Unsworth, British cave diver
Now playing
02:49
Elon Musk sued over 'pedo' tweet
Thai boys rescue video
Thai Navy Seals
Thai boys rescue video
Now playing
01:37
See first video of Thai boys' rescue from cave
Thai Royal Navy
Now playing
01:33
12 boys and their coach all out of Thai cave
Adisak Wongsukchan, father of rescued Wild Boars soccer player Akarat Wongsukchan.
Steve George/CNN
Adisak Wongsukchan, father of rescued Wild Boars soccer player Akarat Wongsukchan.
Now playing
00:57
Father of rescued boy: I want to hug him
CNN
Now playing
01:26
CNN reporter speechless by rescue news
Big Kren Media
Now playing
01:16
New video from dramatic cave rescue
Now playing
01:19
Aunt of trapped coach speaks about his life
Facebook/Akkapol Chanthawong
Now playing
01:36
How the Thai cave saga unfolded
virtual cave foreman
CNN
virtual cave foreman
Now playing
01:31
A virtual look inside the cave rescue
An ambulance leaves the Tham Luang cave area after divers evacuated some of the 12 boys and their coach trapped at the cave in Khun Nam Nang Non Forest Park in the Mae Sai district of Chiang Rai province on July 8, 2018. - Elite divers on July 8 began the extremely dangerous operation to extract 12 boys and their football coach who have been trapped in a flooded cave complex in northern Thailand for more than two weeks, as looming monsoon rains threatened the rescue effort. (Photo by LILLIAN SUWANRUMPHA / AFP) /         (Photo credit should read LILLIAN SUWANRUMPHA/AFP/Getty Images)
LILLIAN SUWANRUMPHA/AFP/Getty Images
An ambulance leaves the Tham Luang cave area after divers evacuated some of the 12 boys and their coach trapped at the cave in Khun Nam Nang Non Forest Park in the Mae Sai district of Chiang Rai province on July 8, 2018. - Elite divers on July 8 began the extremely dangerous operation to extract 12 boys and their football coach who have been trapped in a flooded cave complex in northern Thailand for more than two weeks, as looming monsoon rains threatened the rescue effort. (Photo by LILLIAN SUWANRUMPHA / AFP) / (Photo credit should read LILLIAN SUWANRUMPHA/AFP/Getty Images)
Now playing
01:32
Official: Need more oxygen to finish rescue
(CNN) —  

Billionaire tech entrepreneur Elon Musk shared photos and videos of a metallic pod that may help rescue a group of boys trapped in a cave in Thailand.

Footage shared on Musk’s Twitter account shows a group testing the device in a Los Angeles high school swimming pool.

Musk said in a tweet Sunday evening that the pod — or “kid-size submarine” — was en route to Thailand and would arrive in about 17 hours.

“Hopefully useful,” he said in one tweet. “If not, perhaps it will be in a future situation.”

His updates came after US and Thai officials confirmed Sunday that four boys had been rescued from a flooded cave network after spending 15 days trapped along with their soccer team and coach. They were escorted out by a group of Thai and international divers.

Eight boys and the coach remain trapped, and the ordeal has been a closely watched news story around the globe.

Musk — who runs multiple California-based companies, including SpaceX and Tesla — said Friday that engineers on his staff would travel to Thailand to assess how they might help.

He provided sporadic updates on his efforts over the weekend. Musk said based on “feedback from Thailand,” the engineers decided to build a “tiny, kid-size submarine” using a large silver tube meant to be affixed to a SpaceX Falcon 9 rocket.

Musk explained the metal tube would be “[l]ight enough to be carried by 2 divers, small enough to get through narrow gaps” in the cave, and “extremely robust.” The device is also outfitted with oxygen ports and a nose cone to protect it from impact with rocks, according to Musk’s tweets.

In one of the videos of testing that Musk shared, a man is seen emerging from the roughly 6-foot long metallic cylinder.

There’s been no shortage of warnings in recent days about how risky the rescue attempt is – not least the death of former Thai Navy Sgt. Saman Kunan, an ex-SEAL, who died early Friday morning due to a lack of air while attempting to return to a command center deep underground.

As of early Monday morning local time, rescue efforts were suspended in Thailand as teams restocked supplies and prepared to get the rest of the team out of the cave. CNN’s Jonathan Miller reported that the eight boys and coach who remain stranded in the cave would likely have to stay put for a couple of days due to issues restocking oxygen supplies.

Meanwhile, rescuers have a dwindling window of opportunity, with forecasters predicting the return of heavy monsoon rains in the coming days, effectively sealing off the cave until October.

CNN’s Brian Ries, Meg Wagner, Euan McKirdy, James Masters and Hilary Whiteman contributed to this report.