The head of the U.N.'s International Atomic Energy Agency, who's visiting Japan, says crews are "racing against the clock."
The Japanese government is conceding it was unprepared for a disaster of that scale and was slow to respond. The prime minister is vowing to "rebuild Japan from scratch." He says the disasters have brought a "great test for the Japanese people."
The government is now welcoming U.S. help as it tries to stabilize its overheated, radiation-leaking nuclear complex. It's also raised the severity classification for the nuclear crisis, putting it on a par with the 1979 Three Mile Island accident.
Along the coastline today, sirens wailed to mark one week since the disasters that triggered a nuclear emergency.
There are indications that traces of radiation from Japan have made their way to California, but U.S. government experts insist there's no threat to the American public. They say they're monitoring radiation levels closely.
RELATED: Watch videos of the earthquake and tsunami as they happened in Japan
Emergency Information
For emergency information, assistance, and locating family in connection with earthquake in Japan: http://www.facebook.com/l/6b2e3a9CLMNbUwBsOw1jOL8d5aw/www.jhelp.com
Phone numbers in US and Japan:
202 559 4683
800 373 1110
0570 000 911
011 81 90 7170 4769
011 81 90 3080 6711
