Sept. 21 — U.S. District Judge William M. Skretny allows Tonawanda Coke to stay open, with conditions.
Sept. 17 — Tonawanda Coke found guilty of violating its probation for federal Clean Air Act violations.
Aug. 24 — Federal probation officials report Tonawanda Coke is violating its probation from its 2013 conviction.
July 20 — State says it intends to revoke Tonawanda Coke's permit to operate, cites 176 violations.
June 19 — Federal and state inspectors conduct an on-site inspection.
May 11 — Tonawanda Coke tells state a section of the roof of its coke oven battery waste heat stack tunnel collapsed.
Spring — Neighborhood residents notice unusually thick and discolored emissions from smokestack.
Early 2018 — Tonawanda Coke officials find a partial collapse of the waste heat air tunnel connecting its battery to its battery stack.
April 29-30, 2017 — First samples for Tonawanda Health Study collected taken from 30 backyards in Tonawanda, Kenmore and Buffalo.
April 2017 — DEC proposes expedited cleanup of coal tar deposits.
Dec. 6, 2016 — DEC reports 92 percent reduction in benzene from 2008 levels at a monitor on Grand Island Boulevard and a 74 percent reduction in benzene at Brookside Terrace.
March 19, 2014 — Judge orders Tonawanda Coke to pay $24 million for its conduct and sentences environmental controls manager to a year in federal prison.
Jan. 31, 2014 — Improper maintenance and operations leads to explosion, injuring three workers.
March 28, 2013 — Tonawanda Coke and executive found guilty of polluting the air and ground.
July 30, 2010 — Federal grand jury returns a 20-count criminal indictment charging Tonawanda Coke and executive with federal environmental crimes between 2005 and 2009.