TAIPEI (Taiwan News) — A 27-year-old man identified as Chang Wen (張文) is suspected of throwing smoke grenades and stabbing people at Taipei Main Station, Zhongshan Station, and Eslite Spectrum Nanxi, leaving four dead and 11 injured on Friday evening.

The Ministry of Health and Welfare said that as of 6:25 a.m. Saturday, 15 people that were hurt during the incident had been sent to hospitals in Taipei, per CNA. Of those, four died, six remain hospitalized — including two in intensive care units, three in general wards — while one is under observation in the emergency department.

Taipei Mayor Chiang Wan-an (蔣萬安) on Friday said that a 57-year-old man surnamed Yu (余) saw Chang at Taipei Main Station Exit M7 and tried to intervene, but was fatally wounded and later died, per Liberty Times. The mayor said during a visit to National Taiwan University Hospital that he was “deeply heartbroken” when he spoke to Yu's wife, who said that her husband always stood up for justice.

Chang, when cornered by police on the fifth floor of Eslite Spectrum Nanxi, discarded his knife and tactical vest before falling to the first-floor parking area, per Liberty Times. He was rushed to a hospital, where he was later declared dead at 7:42 p.m. on Friday, per SET News.

Eslite Bookstore issued a statement on Saturday saying the Eslite Spectrum Nanxi store would suspend operations for one day to allow all staff to rest.

A police investigation has so far determined that Chang was unemployed and from Taoyuan. He previously served in the Air Force, but was discharged for drunk driving. He is suspected of breaching the Punishment Act for Violation of the Military Service System, and he was placed on the wanted list by the Taoyuan District Prosecutors Office in July. 

Chang rented an apartment in Taipei’s Zhongzheng District in January. He checked into a business hotel on Nanjing East Road in Taipei on Wednesday, near Eslite Spectrum Nanxi and close to Zhongshan Station.