A church is holding a special mass to pray for a miracle to save the 10-year-old boy who was critically injured in the deadly Sea World Helicopters crash.

Vanessa Tadros and her son Nicholas, 10, were on board the chopper which hit another and plunged to the ground, killing the devoted mother on Monday.

Pilot Ash Jenkinson and British newlyweds Diane and Ron Hughes also died in the crash, but Nicholas was pulled alive from the wreckage.

He was rushed to hospital in a critical condition and has been on life support ever since with his heartbroken father Simon now fearing only a miracle will save him. 

Now the family's St Padre Pio Parish Church at Glenmore Park in western Sydney are holding a dedicated prayer service for Nicholas on Saturday.

Students and teachers from Nicholas's school will join Father Suresh Kumar who said the mass will focus on 'the healing of little Nicholas'.

'He is very critical, very serious,' Father Kumar told the abc. 'All that we can do is pray for a miracle. 

'Doctors are doing their best for little Nicky, but I think only a miracle can save him. His father has requested all of us pray for him.'

He revealed the youngster had only received his communion last year and the community was shattered to find out the family had been hit by the tragedy.

He added: 'It is devastating for all of us. We cannot believe it is at our doorstep.

'When we first heard the news — we hadn't heard the names — that itself was tragic enough.

'When we came to know who it was, it was just terrible.