It's very interesting that some people saw the ship breaking(or exploding) earlier when every funnel was intact,Very interesting sinking process was described by Joseph Scarrott:
"She went slowly down. bow first with a slight list to starboard until the water reached the bridge, then she went quicker. When the third funnel had nearly disappeared I heard four explosions, which I took to be the bursting of the boilers. The ship was right up on end then. Suddently she broke in two between the third and fourth funnel. The after part of the ship came down on the water in its normal position and seemed as if it was going to remain afloat, but it only remained a minute or two then it sank. The lights were burning right up until she broke in two."
Most survivors stories agree with each other. They saw a ship, sinking at an angle of about 60 degress, with all lights still on. Only after the lights went out, survivors stories split into 2 groups.
1 - Titanic sank as Cameron's movie shows it.
2 - Titanic sank as Night to remember shows it.
Emily Ryerson: "The two forward funnels seemed to lean and then she seemed to break in half as if cut with a knife."
Ruth Becker: "...and when I heard the explosion, the Titanic broke in half..."(shows two funnels go away from the other two)
while the others saw the ship breaking in two when the third was nearly underwater.
Mr. CROWE. Two-thirds in the water, one-third of the aft funnel sticking up.
Senator BOURNE. How long did that third stick up?
Mr. CROWE. After she floated back again.
Senator BOURNE. She floated back?
Mr. CROWE. She broke, and the after part floated back.
Senator BOURNE. And the bow part, two-thirds of the ship, sank.
We should also keep in mind that survivors heard two explosions 8-10 minutes apart, and that the survivors' testimonies match together(for example the one Joseph Scarrott mentioned and the person I just quoted), which is impossible if their memory is distorted.
There were two sequences of the breakup, one when all 4 funnels were intact in front of the 3rd funnel, and one when the 3rd funnel was almost underwater, breaking from behind the 3rd funnel.
"Not long after the ship struck there came the first big explosion, then, a moment later, the second. It was this second explosion that did the most damage. It blew away the funnels and tore a big hole in the steamer's side and caused the ship to rock as if she were an eggshell.
This newspaper article from V Break Theory states like this because it was when the break area is more visible from the first, as the bow is already underwater.
I see that most Titanic theories often mix up the two sequences as one, and has only half of both explosions correct from these testimonies.