China's President Hu Jintao arrived in Sichuan province Friday to support earthquake relief efforts. The death toll, now at more than 22,000, is expected to pass 50,000. As Daniel Schearf reports from Chengdu, concern is now turning to providing for survivors.

Chinese Premier Wen Jiabao, left, greets President Hu Jintao, right, upon Hu's arrival in Mianyang, a city in quake-hit southwestern Sichuan province, 16 May 2008

After arriving in Sichuan Mr. Hu went directly to the earthquake disaster zone. China's president joins Premier Wen Jiabao, who greeted him on arrival, in touring areas devastated by Monday's 7.9 quake.

Mr. Wen called the earthquake the most destructive since the founding of the People's Republic of China in 1949.

Speaking on the plane to Sichuan, Mr. Hu assessed the relief situation. He said the challenge is still severe, the task remains extremely difficult and time is pressing.

Thousands of people are believed still buried beneath collapsed homes, offices, and schools. Few of them are expected to still be alive.

In the town of Dujiangyan, a large mechanical digger scoops slabs of concrete and twisted metal rods from a massive pile of rubble.

Volunteers and rescue workers dig through what used to be an apartment building in hope of finding survivors.

China's leaders have vowed to continue rescue work, but as each day passes the odds of finding survivors go down.

Rescue workers have reached the epicenter of the quake, bringing much needed medical, food, and temporary housing supplies.

But, supplies are short and China's weak health care system is struggling to cope with the large number of wounded.

Tens of thousands of survivors are now living on the streets in tents.

Jiang Weixin is China's Minister of Housing and Urban-Rural Development.

He says more than four million homes in Sichuan collapsed or were damaged.

Hundreds of thousands more homes collapsed in neighboring provinces.

Jiang says water, sewage, and electricity networks were severely damaged.

Thousands of aftershocks have set back efforts to clear roads to quake-hit areas.

On Friday afternoon a 5.9 magnitude aftershock hit Lixian, near the epicenter of the quake, cutting off roads and severing communications.