Emergency services were called to the scene at around 2.40am, where three homes had been destroyed in the blast.
Tragically, George Arthur Hinds, aged two years and 10 months, died in the explosion.
Two other people remain in hospital with injuries described as critical.
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Within hours of the explosion, as the wider Heysham area woke up to the devastating news, the community rallied with offers of shelter, money, clothing and other basic items for anyone who had been affected.
Lancaster City Council also opened Salt Ayre Leisure Centre to look after those affected.
Heather Brandwood, from The Hurley Flyer pub, set up a Go Fund Me page which has already raised more than £38,000 for the families affected.
The pub also launched a collection of new clothes and toiletries, and offered meals to those who had been displaced, as well as any emergency service workers.
Heather said: "We have woken up to the truly devastating news of what has happened on Mallowdale Avenue and our immediate thoughts are with the families involved and their friends and neighbours.
"There is no replacing what has been lost, and the devastation has been felt by us all.
"To those on Mallowdale Avenue who have lost their homes, or who have currently been displaced from them for their own safety, you are welcome to join us at the Hurley - don't worry about the next few days for your meals, we will happily look after you whilst you make further arrangements and gather your thoughts."
Another fundraiser set up by Nicola Kenyon has raised £1,405 to help George's family with funeral costs.
She said: "George was a happy beautiful little boy who was sadly taken from his family in an utter tragedy.
"The local community have rallied round today and shown how much support we all can have for one another when needed.
"With permission from George's uncle we have created this go fund me to support Vicki and Steve and try and cover the cost of his funeral which will be one less thing to worry about."
Many people took part in a two minute silence on their doorsteps at 7pm on Sunday May 16, as a mark of respect to the victims of the blast.
Schools in the nearby area also offered support, as well as advice to parents about dropping off and picking up due to the road closures.
St Patricks Catholic Primary School, in Little Avenue, opened for first responders to make a brew or use the facilities on Sunday, May 16.
The school also shared another fundraiser on its Facebook page, which has so far raised £924 for the families affected.
Heysham Mossgate School set up a food and clothing donation point, and said it had received many offers of help and support.
The school said: "What an amazing community we have pulling together during difficult times once again."
Arndale Centre Morecambe posted on their social media page that any residents in Mallowdale Avenue that needed a mobile phone could visit the Vodafone UK store in Morecambe and Lancaster where they would be provided with one for free.
It said: "Our thoughts and prayers are with the residents and families of Mallowdale Avenue.
"If there are any residents that need a mobile phone to keep in touch with loved ones following this tragic accident they can visit the Vodafone UK store in Morecambe or Lancaster where they will be provided with one for free.
If you cannot get to store email [email protected] and delivery will be arranged."
Local firms Move It Men and R Leisure Hire offered free transportation facilities to anyone wishing to donate to the victims of the explosion.
Heysham Co-op in Heysham Road also set up a donation point for food and toiletries.
David Morris, MP for Morecambe and Lunesdale, said he had been in touch with Cadent who are working with BEIS ,the police and fire service and rescue teams to establish the cause of the incident.
He also said he had spoken to Home Secretary Priti Patel, who sent her condolences to the victims and their families and has offered her support and assistance to emergency services staff who attended and continue to work on the incident.
He added: "It is a terrible incident, many of us in Heysham were woken in the early hours to an extremely frightening noise, and the tragic nature of the explosion has saddened us all.
"Our whole community will be supporting each other through this terrible sad time, but make sure if you require support as a result of the incident please do reach out to the council."
As a mark of respect following the explosion, the flags at Lancaster and Morecambe town halls were lowered to half mast.
The Mayor of Lancaster, Coun Malcolm Thomas, said: “The thoughts of the whole council are with those affected by this terrible tragedy.
"I’d like to extend my sincere thanks to the brave members of the emergency services and council staff for their professionalism in dealing with the incident, as well as the community for rallying round to support their friends and neighbours in their time of need.”
Coun Erica Lewis, leader of Lancaster City Council, said: “This is a truly tragic incident and the thoughts of everyone at Lancaster City Council are with the families of all those affected.
“Council officers are working closely with the emergency services and have offered all the support we can to help them to make the area safe.
“The council is also supporting those residents who had to be evacuated from the area and Salt Ayre Leisure Centre is currently open as an evacuation centre.
“Anyone who requires support can contact us on 01524 582000 or 01524 67099.”