Race against time as boys soccer team remains lost in Thailand cave 7 days later

It's been one week since 12 boys and their soccer coach disappeared inside a flooded cave in the mountains of northern Thailand, and rescuers are in a race against time to find them.

Tham Luang Nang Non, Thailand's longest cave and a popular tourist site, is said to be a labyrinth of miles-long passageways and narrow tunnels. Underneath the jungle in Chiang Rai province, the cave can flood up to 20 feet during heavy rain.

Last Saturday afternoon, the group of boys, between the ages of 11 and 16, and their 25-year-old soccer coach hiked into the cave complex after soccer practice. It's believed that the coach often brought his team to the site for fun excursions.

But as the boys and the coach ventured deeper into the cave, the sky opened up and it began to rain.

Authorities believe they crawled through a narrow channel that may now be flooded after days of downpours. Authorities remain hopeful that the group was able to find a chamber that could still be above floodwater levels, with enough air and clean water for them to survive.

More than 1,000 people have been involved in the frantic search and rescue effort, including members of the United States Pacific Command as well as professional cave divers and specialists from the United Kingdom and China. But as Thailand enters its rainy season, persistent rain has hampered the massive operation.

Still, rescuers are intensifying their efforts and doing anything they can -- drilling through the rock, deploying ultrasonic sensors and dropping survival packages down holes they find above ground in hopes the shafts connect to the cave network below.

"There has to be faith. Faith makes everything a success," Thailand's prime minister, Prayut Chan-o-cha, reportedly told families waiting outside the cave on Friday. "Faith in the actions of officials. Faith in our children who are strong and vigorous. Everything will go back to normal."

ABC News' Angus Hines and Hugo Leenhardt contributed to this story.