Question
Can you tell what could have happened to a dumb cane, 'Tropic Snow'...
I have had it about two months.  It seemed fine until 3 weeks ago.  One bottom leave became yellow, then brown.  I removed the leaf.  Then, several of the upper leaves started to turn yellow.  Two days ago, one section fell over and very easily came out of the pot.  This morning the other section fell over. It was about two feet tall.  I watered it twice a week.  It was setting within 3 feet of a gas fireplace.  Not sure if this makes a difference.  It did not have any direct light.  Room temperature is 68 - 70 degrees.  Any advice is appreciated.

Answer
Pat,

I suggest that you remove it from the pot and inspect the roots.  If the roots are black and mushy and appear to be rotting you have overwatered it.  The roots need to breath between waterings and watering twice a week does not allow that.  You are better off watering it well once a week than just a little twice a week.  
If the roots are healthy it may have been too little light or the effects from your gas fireplace.  This plant seems to be sensitive to air pollution.  And if your hand will not make a good shadow in a location there is not enough light to grow a plant. They will survive awhile then collapse.  Good luck at figuring it out and let me know what you decide the problem was.  Inspect the roots first, then check the light in that location.  

                                         Darlene