Cherry tree grove failure in Kanemoto Park

I haven't seen this mentioned anywhere but only one of the cherry trees planted two years ago in Kanemoto Park have survived.  The rest have been cut down.  I first noticed them in May 2009 and they were prominent at the Jimmy Kanemoto dedication last year, in August.  I've read where the trees were donated by the Longmont Sister Cities Assocation (LSCA).

This is from August 2010, where they appeared to be doing well:

And from today, only one tree is left (near the monument):

The survivor:

The rest have been cut down:

  
Although one of them is trying to make a comeback on its own:

 There appear to be some new trees planted on the grounds outside the squared-off area.  Other than guessing that some replacement trees were planted where they would get better irrigation, I'm not sure what's going on.  Or perhaps the Kwanzan Japanese Flowering Cherry (Prunus serrulata Kwanzan) are difficult to grow here?

I'll have to ask the City what happened, and will post a followup if I find out.