>>> now to the other front we are covering tonight and have been for days on end. we shift our coverage to boulder, colorado , where today they officially set the all-time record for rainfall. it has resulted in a desperate situation there, as you know. the latest numbers from there are grim. seven people confirmed or presumed dead . at least 19,000 homes destroyed or damaged to say nothing of the estimated 30 bridges that are out. most urgently, hundreds of people are still officially unaccounted for. in a moment, an extraordinary view of it all from just above the unfolding situation. but first the very latest from the ground against this fight against water in boulder, colorado . our national correspondent kate snow is there for us tonight. kate, good evening.

>> reporter: good evening, brian . it is believed to be the most massive aerial search and rescue effort since hurricane katrina . all afternoon helicopters ferried people out of neighborhoods and towns completely shut off from the outside world . there are still more people waiting.

>> we have a long ways to go, folks.

>> reporter: before dawn this morning dozens of agencies coordinated rescue plans, hoping the rain that pounded boulder overnight and all day sunday would finally let up.

>> the helicopters are ready.

>> reporter: by mid-morning, a break. battalion leader lieutenant colonel tyler smith suited up and took off in search of the most vulnerable.

>> once you cross into the mountains you can see the water flow. many roads are washed out. people are stranded geographically.

>> reporter: stranded until today. our cameras were on board for the rescue. children with backpacks, families with pets, people in wheelchairs and walkers, all back on high ground . they have been told to write s.o.s. messages on the driveways, use sheets or flags, anything to draw a chopper's attention.

>> anything you can do to get our attention, we'll stop.

>> reporter: the roads are treacherous and only go so far. we headed up left-hand canyon in military vehicles with a search and rescue squad out of utah. do you know if there are a lot of people in there or you have no idea?

>> we don't know. my understanding is it's an area that hasn't been looked at yet.

>> reporter: the team finds homeowners who want to stay put.

>> they are recommending evacuation. there obviously won't be ser vises available to you for they don't know how long.

>> reporter: five days in there are entire towns cut off. for the first time we are seeing what life is like in jamestown.

>> the creek kept rising. it started taking out houses. we watched one by one houses just cracking off and going into the creek.

>> reporter: at boulder's command center they are reaching some people using ham radio s.

>> everything okay? water, whatever?

>> we have no way of re filling the tanks. once the water runs out, it's going to get bad.

>> reporter: trying to make contact with the missing, one person at a time. mike horn thought his wife of 38 years, florence, was missing. water rolled their house into the river. they were separate ed.

>> he said, where's your wife. i said, i think she 's lost.

>> reporter: but she survived, rescued by a good samaritan.

>> the most brave man in the world to jump in that water.

>> reporter: the good news tonight is as people are connecting with rescuers, connecting with law enforcement , they are finding out those people are accounted for. the number of unaccounted is going down. the bad news, the governor thinks the death toll will rise here. brian , tonight there is still a flash flood watch in effect for parts of colorado . brian ?

>> kate snow starting off our coverage from colorado . thanks.