1775: the Revolutionary War breaks out as General Gage sends a force to seize militia supplies, and the Americans resist.
1993: the final day of the Waco siege. FBI armored vehicles fill the Davidians' building with CS gas and methylene chloride, a fire breaks out, and over a hundred die.
1995: Timothy McVeigh sets off his bomb at Oklahoma City, killing 168.
2015: the Washington Post remembers one of the above.