Mark BOM components with 1 where BOM's Stop Explode is marked as 1

Question

CREATE TABLE [dbo].[ItemStopExplosion](
[Item] [nvarchar](10) NOT NULL,
[BOM] [nvarchar](5) NOT NULL,
[LevelNumber] [int] NOT NULL,
[LineNumber] [int] NOT NULL,
[StopExplode] [int] NOT NULL
) ON [PRIMARY]
GO
INSERT INTO [dbo].[ItemStopExplosion]
(Item,BOM,LevelNumber,LineNumber,StopExplode)
VALUES
('A','YES',1,1,0),
('B','YES',2,2,0),
('C','NO',2,3,1),
('D','NO',2,4,0),
('E','YES',1,5,0),
('F','NO',2,6,0),
('G','NO',2,7,0),
('H','YES',2,8,1),
('I','NO',3,9,0),
('J','NO',3,10,0),
('K','NO',3,11,0),
('L','NO',2,12,0);
Hi,
I've a sql query question and I hope some one could help me, could be as simple as using a CTE or something else but I cant get this one.
For the above mentioned data, whenever an Item has BOM=Yes and Stop Explode=1, I need to mark the sub-parts as stop explode (i.e. 1) as well. The catch is,
once the level of the items reach the same value as the BOM that initiated the process, the marking should stop. So for example in the above scenario, the final result would look like this. 
Any ideas?

Answer 1

CREATE TABLE [dbo].[ItemStopExplosion](
[Item] [nvarchar](10) NOT NULL,
[BOM] [nvarchar](5) NOT NULL,
[LevelNumber] [int] NOT NULL,
[LineNumber] [int] NOT NULL,
[StopExplode] [int] NOT NULL
) ON [PRIMARY]
GO
INSERT INTO [dbo].[ItemStopExplosion]
(Item,BOM,LevelNumber,LineNumber,StopExplode)
VALUES
('A','YES',1,1,0),
('B','YES',2,2,0),
('C','NO',2,3,1),
('D','NO',2,4,0),
('E','YES',1,5,0),
('F','NO',2,6,0),
('G','NO',2,7,0),
('H','YES',2,8,1),
('I','NO',3,9,0),
('J','NO',3,10,0),
('K','NO',3,11,0),
('L','NO',2,12,0);
;with mycte as (
select item, BOM,LevelNumber,LineNumber,StopExplode
, row_number() Over(partition by LevelNumber Order by Item) - row_number() Over(partition by LevelNumber,StopExplode Order by Item) island
from [ItemStopExplosion]
,mycte1 as (
select item, BOM,LevelNumber,LineNumber,StopExplode,sum(island) Over(Order by item) amt from mycte
Select item,BOM,LevelNumber,LineNumber,StopExplode
, sum(Case when BOM='YES' and StopExplode=1 then 1 ELse 0 END) Over(Partition by amt Order by item) NewStopExplode
from mycte1
Order by item
drop table [ItemStopExplosion]