KAOHSIUNG, Taiwan (AP) — The 12,000 people who fled in fear of more gas pipeline explosions in Taiwan’s second-largest city returned to their homes Friday after authorities said there was no more risk of blasts like the series that ripped apart streets overnight, killing 26 people and injuring 267.

With clean-up work underway in the more than 2 square kilometers (1 square mile) area, investigators were turning to the task of determining the cause of the blasts, the industrial city’s worst such disaster in 16 years.