4 and 430 on Cairo 7. A advisory panel told Congress, I have never been as concerned for space shuttle safety as I am right now. NASA officials insist that safety is their primary concern, and many members of Congress believe that's true. There is absolutely no evidence that I have heard to date that safety has been compromised at all by the amount of money that's been spent. But Don Nelson, a retired NASA engineer who helped design the shuttle, bitterly disagrees. He claims NASA failed to respond to repeated signs that an aging shuttle fleet was heading for another disaster. Last August he wrote President Bush urging him to place a safety moratorium on shuttle flights saying, your intervention is required to prevent another catastrophic space shuttle accident. You've got to realize this, this is a very risky business and there has never been a launch vehicle that has gone more than 100 flights before we've had a catastrophe failure in it. No one can yet say if this was a result of a lingering safety issue or just a bolt out of the blue that nothing could have prevented. President Bush will propose a $500 million increase in NASA funding in his budget to be presented later today. But congressional leaders have vowed if this was a safety issue related to funding, it will be addressed aggressively. John Roberts, CBS News, the White House. President Bush will lead the nation mourning the loss at a memorial service tomorrow at the Johnson Space Center in Houston. CBS's John Blackstone reports. As the nation mourns the loss of seven astronauts, people in Houston are mourning the loss of seven neighbors. The suburbs around the Johnson Space Center have been the home of astronauts since the space program began. Jeffrey Williams flew on space shuttle Atlantis. There's nobody in the area that's not affected in some way. The space program becomes personal when astronauts live just down the block. You see them out mowing their yard. You see them at the grocery store. This is really a company town in a way, I suppose. Something like this touches everyone here. Very close. And I think at this time is when we all do come together and hold each other up and put our arms around each other. So tight knit that at Grace Community Church, Reverend Steve Riggle lost two parishioners on Columbia. Two members of one church on that craft. Incredible. Unbelievable. Both Columbia's commander, Rick Husband, and mission specialist Mike Anderson worshiped at Grace. That's the amazing thing that in this congregation, they're just normal people. Rick Husband sang in the choir and often spoke to young people in the church, among them 14-year-old Shelly Bradley. When they at the end said there were no survivors, I was just heartbroken. But the tragedy hasn't changed the ambition of a girl who's grown up among space travelers. You thought of being an astronaut? Still do. Still think of being an astronaut? Mm-hmm. Even as it copes with loss, this company town is also a place determined that the manned space program will go on. John Blackston, CBS News at the Johnson Space Center. I have a real pet peeve about oral hygiene. Not many people think about it for their pet. Our best friends, the ones who never complain no matter what, are dogs and cats. We need to think about them. 85% of adult pets suffer from some form of periodontal disease. Chronic pain and even life-threatening problems can be prevented with daily brushing and regular teeth cleaning from your veterinarian. Dental health. Make it your pet project. I have. Contact your veterinarian today for your pet's healthy tomorrow. You did great on that test, son. I'm real proud of you. Now, John DePauw! Be encouraging. Get them to graduate. Don't drop out on your kids. For more tips to keep them in school, call 877-4-A-KID. My dad died in 06. Then my mom and my little brother. He was born with it. They both got sick and died. This is the room my big sister died in. She had it the worst. She held on for a long time. And I took care of her. Nobody came to help us. We didn't know what to do. Where's dinner? Well, I thought you'd be home a couple of hours ago and I put everything away. What is this? Pizza? You had just called me. Dinner ready is pizza. Honey, please don't be so loud. Please don't. Let go of me! Get in the kitchen! No! You want to see what happens? Stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! I said stop! Stop! Stop! Stop! That's what hurts! That's what hurts! Oh, please! I can't! Please! For information, call 1-800-END-ABUSE. It is ten minutes past the hour. The investigation of the Columbia tragedy has found so far that the left side of the shuttle experienced a sudden abnormal rise in temperature. One of the details investigators will examine is the relationship between the wing flap or elevant sensors and the left wheel well, one of the more vulnerable areas of the shuttle's underbelly. As we are starting to look at the trail of this wiring as it goes through the fuselage and out to the elevant, it has a common point as it goes adjacent to the wheel well. That's interesting to us. That's all we know today. So as we go through the coming days, maybe I'll get more information to add to this puzzle. I don't have any more than what I told you today. I don't want to speculate any more than the information I gave you. Be cautious. I know I'm thinking the same thing you're thinking, but I can't go beyond that. CBS News space consultant Bill Harwood was the first to tell CBS News that something had gone horribly wrong Saturday morning. And the one who put that question to Ron Ditmore, head of the space program. He was at the Kennedy Space Center in Florida awaiting Columbia's return. Bill is now at the Johnson Space Center in Houston. Good morning, Bill, and thank you for joining us. Good morning, Bonnie. When did you first notice something was wrong? What did you notice? It was right at 9 a.m. Eastern time. You know, 16 minutes away from landing, mission control had talked to the crew just a few seconds earlier and then there was some radio silence. That's not necessarily unusual. They can occasionally lose the signal to the satellite and I'm familiar with that. It's a few minutes drug by I began to start wondering why they couldn't talk to them. I have a friend, Justin Ray, at spaceflightnow.com, who we maintain an internet instant messaging chat if you will during launches and landings. And he sent me a note asking me if I was getting nervous. I sent a note back saying I was beginning to. And then he forwarded me a message from a friend of his in Texas who reported literally, oh my God, in capital letters with exclamation points, I think the shuttle has broken up. He had watched it in Texas up high in the sky as it came apart. And of course, you just get a chill in your bones when you see something like that. I knew from the lack of radio communications that something clearly had gone wrong. And then when they got within range or should have been within.