A furniture shop owner has been jailed for 20 years for causing a “colossal” explosion that injured 81 people in an attempt to claim insurance.

Pascal Blasio, 57, of Gillingham in Kent, caused the blast at his furniture store in New Ferry, Wirral, Liverpool crown court heard on Wednesday. Sentencing him, the judge, Thomas Teague QC, said: “You have exhibited human selfishness in an almost chemically pure state.”

The businessman was found guilty after a trial of causing an explosion likely to endanger life and of fraud in relation to an insurance claim for more than £50,000.

Pascal Blasio. Photograph: Merseyside police/PA

The blast happened when Blasio opened a valve in his Homes In Style shop to release gas and switched on an electric fire at about 9.15pm on Saturday 25 March 2017, the court heard. It destroyed or damaged 63 properties.

“You did not care who else might suffer as long as you could swindle the insurers out of £50,000, money to which you knew perfectly well you had no right,” said Teague.

The judge described the blast as “colossal” and said it “annihilated” the furniture store and dance studio above it, as well as in effect reducing an entire block of buildings “to rubble”. He said it was a “remarkable stroke of sheer good fortune” that no one was killed.

Blasio, whose wife was in tears in court, sat with his head against the glass panel of the dock at times during the hearing and shook his head as the judge read his sentencing remarks.

The court heard that among the 81 victims of the explosion was Lewis Jones, who was waiting at a bus stop when the blast happened and sustained a serious brain injury. “He was left, literally, clinging to life,” the prosecutor, Henry Riding, said.

Jones, who was 21 at the time, was in court for the hearing along with other members of the community.

Ian Brown, who had been having a meal in a Chinese restaurant opposite the furniture shop when the explosion happened, told the court it felt like a terrorist attack. “It was a complete scene of devastation and there was complete pandemonium. The air was thick with dust, you couldn’t see,” he said.

The court heard a number of statements from residents describing the impact of the injuries and damage to properties.

Kim Ashwin, co-owner of a dance studio above the shop, said if the blast had happened earlier in the day or on any other night of the week there could have been 100 children and their families inside.

In a statement Neil Mitchell from Wirral council environmental services said: “The explosion in March 2017 was probably the most significant disaster that the council and emergency services in the borough had ever faced in peacetime.”

David Mason QC, defending, said Blasio, who has seven grandchildren, had suffered intimidation from inmates in prison while on remand. “Mr Blasio has lost everything now, his family will suffer,” he said.

Blasio was sentenced to 20 years for causing the explosion and given a concurrent sentence of eight years for the fraud.

Speaking outside court, Christopher Power, a New Ferry resident whose home was damaged in the explosion, said: “We have a long way to go. Yes, it may be closure on this part, but we have to live now and we have to rebuild our lives. He took away our lives and that’s upsetting.”

Natalie Perischine, a Merseyside police assistant chief constable, said: “I sincerely hope that the sentencing of Blasio today means people of New Ferry can now start to draw a line under that fateful night and begin to rebuild their lives in the knowledge that Blasio will spend a considerable amount of time in prison paying for his greedy and selfish actions.”

Blasio originally stood trial in January but the jury was discharged after being unable to reach a verdict and a retrial began last month.

Before his trial, Contract Natural Gas pleaded guilty to an offence under the Health and Safety at Work Act 1974 by failing to ensure that gas supply pipes were disconnected.

The company was fined £320,000 and ordered to pay £50,000 towards the prosecution costs.