>>> however, our attention is focused to the west in the reeockies. a desperate situation truly in and around boulder, colorado . a rising death toll, rising water. people both stranded and listed as missing. sadly, no stop to the water. nbc's miguel almaguer is in boulder tonight to start us off from there. miguel , good evening.

>>> brian, good evening. this is the boulder creek . tonight it is a raging river . it is torrents like this that claimed at least four lives. some 80 people are unaccounted for. while the rain here has stopped for now, the threat, the danger has not. surrounded by surging rapids, several communities along colorado 's front range are islands. locals pleading for help he any way they can.

>> an hour ago that road was there.

>> reporter: a harrowing rescue at big thompson canyon . emergency crews used a zip line to bring this woman to safety. the national guard deployed to evacuate the town of lions. 1600 people trapped by rising water. are you happy to be on dry land , safe?

>> yeah.

>> reporter: 9-year-old alexandria, her mom and sib siblings.

>> you're trapped.

>> reporter: with damage as farce as the eye can see, many remain trapped, some unaccounted for. holly stetson is worried. she hasn't heard from her father.

>> we are anxious to get any word and see if he's okay.

>> reporter: this is the reason why the national guard can't reach so many residents. roads have literally been washed away. this afternoon, helicopters became air bus withes. the governor says the flood stretches 130 miles.

>> even just a foot and a half of water can knock people over. if possible, stay off the roads.

>> reporter: in a university town , not everyone listens. with nearly a year's worth of rain in a single day, cities like longmont face an historic and catastrophic flood. some creeks and rivers are running 50 times above normal. evacuees got out any way they could.

>> i had three boat rides, one surfboard, motorboat and a that canoe.

>>> we found lindsay looking at the road.

>> it was absolutely terrifying.

>> we were lucky to get out. my neighbor two doors down is missing.

>> reporter: they rounded up molly, mr. fin and dr. watson as he took a last look at his home. what do you do now?

>> well, one step at a time.

>> reporter: tonight flowers is safe but worried as new storm clouds move in. miguel almaguer, nbc news, boulder, colorado . this is