JOPLIN, Mo. - Crews busted holes in concrete slabs and sifted through strewn home goods Tuesday as rescuers focused on crumpled big-box stores and apartment complexes in Joplin in a frantic search for survivors of the deadliest single U.S. tornado in about 60 years.
With 122 confirmed dead and 750 people hurt thus far from a tornado officials have rated an F5 - the strongest possible - several reports have put the number of missing as high as 1,500.
The large number of missing people most likely has to do with destroyed communications systems and the inability of family members to be in touch with those missing, a local official said late Tuesday. Many of the 1,500 missing may have simply scattered when the weather hit and not had an opportunity to report their whereabouts. The missing people are by no means necessarily injured or deceased, the official said
"When we open up the area and start letting them come back in ... that number of unaccounted for will start to dwindle," an official said.
One team poked through the remains of a Home Depot store, while others searched a Walmart and wrecked apartments as the clock ticked down on another round of severe storms. A hunt through the rubble using search-and-rescue dogs was planned, and officials expected to test the city's nine warning sirens while the sun was still shining.
The Storm Prediction Center in Norman, Okla., warned of severe weather starting Tuesday afternoon in a band from northern Texas up to southern Illinois and stretching east into western Kentucky, western Tennessee and northwest Mississippi. Meteorologist David Imy said conditions were ripe for tornadoes in central and eastern Kansas, almost all of Oklahoma and northern portions of Texas.
Video: "I'm alive" text saves man from rubble
Video: Joplin twister seen through survivor's video
"It looks like primetime for the greatest tornado coverage and intensity will be between 3 to 4 p.m. and 9 to 10 p.m.," Imy said. "That will be when the greatest coverage and most intense storms occur."
Another top job was testing the city's tornado sirens to make sure they were operable ahead of another round of potentially violent weather starting Tuesday evening and expected to last into Wednesday in some places. Emergency officials warned jittery residents well in advance of the test.
David Imy, a meteorologist at the federal government's Storm Prediction Center in Norman, Okla., said conditions were ripe for severe thunderstorms, including tornadoes, in parts of Kansas, Missouri, Arkansas, Texas, Kentucky and Tennessee, as well as nearly all of Oklahoma.
The massive tornado that ripped through the heart of the blue-collar southwest Missouri city of 50,000 people on Sunday was the deadliest on record in nearly six decades.
Sam Murphey, a spokesman for Gov. Jay Nixon's office, said Tuesday that 117 bodies had been found but he didn't know when or where the latest one was discovered. Fire chief Mitch Randles said he knew of only 116 bodies found.
The governor told Chris Wragge, co-anchor of CBS' "The Early Show," Tuesday morning that, weather permitting, rescue crews hoped to have combed over "every foot of this town" by the afternoon.
Nixon said he did not want to guess how high the death toll would eventually climb. But he said: "Clearly, it's on its way up."
There were glimmers of hope. CBS News correspondent Cynthia Bowers reports that at least 17 people have been pulled from the twisted rubble alive.
Nixon has said 17 survivors have been found, but Randles said he knew of only seven.
"We're getting sporadic calls of cries for help from rubble piles ... most of those are turning out to be false," Randles said.
Officials say, however, at least 130 are still unaccounted for.
Late Sunday night, a man trapped inside a building by debris was rescued after he sent a text message to his best friend about his situation, CBS News reports. The trapped man wrote "I'm alive" in the message. That helped lead search-and-rescue crews to the center of Joplin, where they found him.
Rescuers found one person alive at the Home Depot on Monday, but they also discovered seven bodies under a concrete slab, officials said. Search-and-rescue team leader Doug Westhoff said team members have searched as much of the store's interior as they can and are now focused on what is under collapsed concrete slabs that once helped hold up the store. After the holes are drilled, dogs will be brought in to try to detect any human scent.
On Tuesday, nursing home operator Bill Mitchell said that 10 patients and a staff member were killed when the facility was demolished by the twister. The survivors were sent to other facilities in Arkansas, Oklahoma and Kansas. Mitchell said one person remains unaccounted for.
Randles said teams were taking advantage of the best weather they'd had in two days to go through every damaged and destroyed building. After seven people were pulled from rubble Monday, he and others said they hoped to find more survivors.
"It's really incredible the fact that we're still finding people," Randles said.
Westhoff also expressed hope, but said the outlook at the Home Depot was bleak because of the size of the slabs and magnitude of the collapse.
People in Joplin and beyond have turned to online social networks as they try to find relatives missing since the tornado struck, or simply because they're curious.
Multiple Facebook pages created since the tornado are filled with requests for information about people who haven't been heard from since Sunday, sometimes including photos of the missing. Other posts on the same pages share news about Joplin residents who are alive and well.
Several social-networking efforts specifically focus on finding information about Will Norton, a teenager who is reported to have been sucked out of the sun roof of a car on his way home from a graduation ceremony. More than 10,000 people like the "Help Find Will Norton" community page on Facebook, and Twitter users are tweeting heavily about the missing teen.