There is a bit of intertwining between the little boy who died in the orphanage fire and my Belasco forebears. I have discovered:
1) In 1871 the head of the orphanage was Phoebe Belasco. Her granddaughter Sarah Levy lived with her there along with 11 boys, including a Benjamin Martin, who may or may not have been related to Henry.
2) In 1881 the heads of the orphanage were Lewis and Rebecca Levy, who were in charge of 12 boys, among them my great uncle Guerschon - various spellings of this in different records - (a.k.a. George) Belasco aged 12, and an Aaron Martinez aged 14. There is no mention of a Henry (or a Haim), though. Maybe he arrived after the 1881 census was taken, and I've no idea whether Aaron was related to him. So I don't know whether the paths of Guerschon and Henry ever crossed in the orphanage, its school, or elsewhere.
3) Henry's father, David Nunes Martinez (1828 to 1881) and his mother Elizabeth Lewis (1835 to 1899) were married in London City (Bevis Marks, maybe?) in 1850 and had 8 children, including Henry, between 1853 and 1879. As Henry died in the fire in 1882, by then only his father was dead, not his mother. But of course it was quite normal in those days for a widowed parent to have to place offspring in orphanages. In fact, I have discovered that some inmates of 'orphanages' were not in fact orphans, it was just that their parents hadn't the means to care for them or, in some cases, they were placed there because they were born out of wedlock.
4) Going back further: Sarah Nunes Martinez (1771 to 1833) married Joseph Belasco - one of many Joseph Belascos in 'my lot'! - (1768 to 1823). They had 9 children, one of whom, Jacob Belasco (1804 to 1875) married Agar Nunes Martinez.
As you may have discovered, among tight-knit communities there was often a lot of intermarriage between families. Certainly among 'my' Belascos, the same surnames keep cropping up time and time again, and in one instance a male Belasco marrying a female Belasco first cousin, not to mention a number of instances of two brothers marrying two sisters, or two cousins marrying two cousins, or .... etc. etc.
As I understand it, in Jewish law a man is not supposed to marry a deceased brother's widow. But that did happen at least once among the Belascos, and they were in deep water for it, and had to get a special dispensation from a rabbi to legalise their marriage - after they had had several children!
Well, there we are, more fascinating bits about 19th century British Jewry.
Good wishes, Clive