The gigantic sinkhole, measuring around 30 metres (98 feet) wide and 15 metres deep, appeared last Tuesday in a bustling business district in the southwestern city of Fukuoka, swallowing part of a five-lane street.
The sinkhole, apparently triggered by subway construction in the area, had exposed the support columns of nearby buildings at a traffic intersection.
Japanese workers toiled continuously for a week, dumping huge amounts of wet cement and sand into the gaping hole and fixing electricity, gas and water lines that had stopped following the accident.
The street reopened at 5 AM on Tuesday according to a statement by Fukuoka Mayor Soichiro Takashima, exactly a week after the ground began sinking.
"We're very sorry for causing great trouble," Takashima said, noting that a ban on access to surrounding buildings was lifted.
Many on social media expressed amazement at the quick recovery.
"I'm surprised the road reopened in a week!" one Twitter user said.
"Impressive. That was fast," another said.
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