New York emergency workers are searching for at least two people still missing after an apparent gas line explosion levelled three apartment buildings and injured 22 others.
Special canine units on Saturday will sniff for anyone possibly trapped beneath the heap of loose brick and rubble.
Detectives have issued posters seeking information on the whereabouts of two men believed to have been in the sushi restaurant on the ground-floor of one of the now-collapsed buildings: a 26-year-old worker at the restaurant and 23-year-old bowling alley worker who had been there on a date.
Authorities also were exploring whether a third person was unaccounted for, Chief of Detectives Robert Boyce said.
"There's a lot more we need to learn," Mayor Bill de Blasio said on Friday, a day after the blast in Manhattan's East Village neighbourhood.
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It's possible someone improperly tapped a gas line amid ongoing work in one of the destroyed buildings, though investigators need to get into the basement to learn more.
Consolidated Edison utility inspectors had visited the work site about an hour before the blast and determined the work didn't pass inspection.
They locked the line to ensure it wouldn't be used before leaving, officials said.
But 15 minutes later, the sushi restaurant owner smelled gas and called the landlord who called the general contractor, Boyce said. Nobody called emergency services or Con Ed.
The contractor, Dilber Kukic, and the owner's son went into the basement and opened a door, and then the explosion happened, burning their faces, Boyce said.
Kukic, who is facing an unrelated bribery charge, declined through his lawyer to comment.
The building had an existing gas line intended to serve the sushi restaurant; the work underway was to put in a bigger line to serve the entire building.
