At 7am on Saturday morning, May 10, I watched one of the tiniest, quietest, least gregarious and yet most poignant processions I've ever seen, at Ground Zero, New York.  

Police motorcycle outriders guided a trio of vehicles each containing one of three caskets.  

Each of the three was draped with "Old Glory" and inside were some of the unidentified remains of people who died here at the World Trade Center in lower Manhattan when the planes went in almost 13 years ago.  

In front of the flag painted doors of the fire department's "10 House" (Engine 10 and Ladder 10) the newest members of New York's bravest were fighting back the tears and saluting.  

Family members watched the coffins descend seven floors down into the new national 9/11 memorial museum which opens this Thursday, May 15.

National 9/11 Memorial Museum  

From the second it happened in September 2001 there's never been any doubt a museum would be built here to serve as a focus for mourning the loss of almost 3,000 people - including those who died at the Pentagon and Shanksville, Pennsylvania.  

The only question has been what kind of museum it would be? Well, now we know but predictably it's not without controversy.  

I could tell you about the outrage surrounding the $24 entry fee - the fact that it's been built on a flood plain - or the $40 trinkets on sale in the gift shop.  

But there are two key criticisms that make New Yorkers really angry.  

Unidentified remains  

Chief among them is that 8,500 unidentified human remains - representing everyone who never came home that day and whose bodies have not been logged by the medical examiner - are being stored inside the museum, seven floors down, without an eternal flame and in a facility that will be locked up at night.  

The city says it consulted the five families who sit on the 9/11 board ... but many 9/11 families want a poll among all 2,700 families who lost loved ones to see what the majority wants to happen to the remains.  

On Saturday morning some family members placed black elastic armbands over their mouths to signify that they feel they've been given no choice and no voice on where the remains end up.  

Former deputy fire captain, Jim Riches, lost his son Jimmy on 9/11. He was there, nine months later, when Jimmy's body was pulled from the wreckage of the North Tower. His crushed helmet is now an exhibit at the museum - donated by his dad.  

Jim says, "It's going to be a powerful museum, they don't need these P.T. Barnum productions of putting human remains in the museum. Let's show what happened that day, tell the story of the day ... and memorialise our loved ones".

Rosaleen Tallon lost her brother Sean 13 years ago. She says, "I think they deserve something beautiful because they never got a chance to go home to their family cemeteries. Of all the remains from 9/11 these are the ones that should be given the most beautiful the most dignified place to rest."

"The Rise of al-Qaeda"  

The other battle involves Muslims who are unhappy at a film titled, The Rise of al-Qaeda that plays as an exhibit.  

An interfaith council invited in to review the museum found most of it to be inspiring but the committee says the film unfairly links Islam with terrorism - something that should be rectified.  

Chloe Breyer who heads up the Interfaith Center of New York says, "Having a disclaimer of some kind that said this is not representing Islam ... or show someone like an American Muslim New Yorker saying my faith tradition has been negatively impacted by what happened on 9/11 and I have been lumped with this group of people whom I have nothing to do with - having that statement on tape would have given such a fuller picture."  

As of now there are no plans to add such a disclaimer nor add a clarifying interview with an Islam worshipper.  

Obama to attend opening  

Of course nothing is set in stone - everything can be updated over time. On Thursday the 9/11 families and President Obama will view the exhibits for the first time.  

It will be an emotional day because down there, close to the bedrock of Ground Zero, it's as if the events of September 11, 2001 have only just taken place - it's a moving experience!  

Should it be a pay-to-enter attraction? Should the unidentified remains be there?  Should it have been built on a flood plain? Should the staff salaries be as high as they are? (The first $12m off the annual budget of $60m.)  

These are all good questions for the future - but for now - despite all the criticism and heartache - what can be said is that the national 9/11 memorial museum provides the US with a renewed focal point for anyone wishing to re-live that day in 2001 when the world changed forever.