TAIPEI (Taiwan News) — Prosecutors charged 11 people over the deaths that occurred in a gas explosion at a Taichung mall in February.

Prosecutors on Monday charged a team leader at the Shin Kong Mitsukoshi mall where the blast occurred and released him after he posted NT$400,000 (US$12,310), per ET Today. The man, surnamed Hsieh (謝), became the 11th person charged after 10 others and posted bail ranging between NT$100,000 and NT$600,000.

The late-morning explosion on Feb. 13 tore through a mall as contractors worked on the 12th floor. Two visitors from Macau were killed on the first floor by falling debris, and their granddaughter died later from her injuries. Two mall workers were also found dead on the 11th and 12th floors.

Prosecutors said in a press release last week that preliminary investigations found careless construction work caused the explosion. They said this caused a gas leak, which was ignited by sparks from a power tool.

Prosecutors charged the defendants with manslaughter, negligence causing injury, and negligence destroying property. Those charged were construction contractors and Shin Kong Mitsukoshi staff, including the store’s manager, and all were banned from leaving Taiwan.

The gas company that supplied the building has maintained the gas was turned off before the explosion, while the Taichung fire department said on-site inspections and discussions with experts concluded a gas leak was the cause. The fire department said last week that those responsible for turning off gas leak monitors in the mall were fined.