AP Photo/File Volcanic ash and steam rises from Mount St. Helens, Wash., as it erupted, May 18, 1980.

Today is Monday, May 18, the 138th day of 2026. There are 227 days left in the year.

Today in history:

On May 18, 1980, the Mount St. Helens volcano in Washington state erupted, leaving an estimated 57 people dead or missing.

Also on this date:

In 1863, the Siege of Vicksburg began during the Civil War, ending on July 4 with a Union victory that gave its forces control of the Mississippi River.

In 1896, the U.S. Supreme Court, in Plessy v. Ferguson, endorsed “separate but equal” racial segregation. (The decision was reversed in 1954 by Brown v. Board of Education of Topeka.)

In 1927, in America’s deadliest school attack, part of a schoolhouse in Bath Township, Michigan, was blown up with explosives planted by local farmer Andrew Kehoe, who then set off a bomb in his truck; the attacks killed 38 children and six adults, including Kehoe, who’d earlier killed his wife. (Authorities said Kehoe was seeking revenge for losing a township clerk election.)

In 1933, President Franklin D. Roosevelt signed a measure creating the Tennessee Valley Authority, the largest public utility in America.

In 1973, Harvard law professor Archibald Cox was appointed Watergate special prosecutor by U.S. Attorney General Elliot Richardson.

In 1981, the New York Native, a biweekly newspaper directed toward gay men and lesbians, carried a story informing of “an exotic new disease” among LGBTQ+ people; it was the first published report about what came to be known as AIDS.

In 1998, the U.S. government filed an antitrust case against Microsoft, saying the powerful software company had a “choke hold” on competitors that was denying consumers important choices about how they bought and used computers. (The Justice Department and Microsoft reached a settlement in 2001.)

In 2018, a 17-year-old armed with a shotgun and a pistol opened fire at a Houston-area high school, killing eight students and two teachers.

In 2018, a Boeing 737 chartered by Cuba’s national airline from a Mexican company crashed a short distance from Havana’s Jose Marti Airport, killing all but one of 113 people on board. Cuban aviation officials later said errors in calculating the weight and balance of the plane led the crew to lose control of the aircraft during takeoff.

Today’s Birthdays: Baseball Hall of Famer Reggie Jackson is 80. Musician Rick Wakeman (Yes) is 77. Musician-composer Mark Mothersbaugh (Devo) is 76. Country musician George Strait is 74. Actor Chow Yun-Fat is 71. Hockey Hall of Famer Jari Kurri is 66. Tennis Hall of Famer Yannick Noah is 66. Comedian-writer Tina Fey is 56. Rock singer Jack Johnson is 51. Figure skater Alina Zagitova is 24. Heisman Trophy winner Travis Hunter is 23. Actor Hala Finley is 17.