This week in history: Mount St. Helens erupts

• As the mountain blew, Washingtonians saw an apocalyptic landscape with ash and debris falling from the sky over 24 square miles.
• "There was such a surreal feel to it all; it was like watching the end of the world come slowly, and you could do nothing but watch," eyewitness Lee Harris told the Seattle Post-Intelligencer.
• Of all the Northwest's active volcanoes, Mount St. Helens is the most likely to have another eruption, per USGS. But active monitoring of the mountain means we'll have some advance warning if it does.

May 20, 1977: The Seattle Aquarium became the city's first municipal aquarium, opening on the waterfront after some controversy over where it might go.

• Ballard's Golden Gardens was also considered as a potential site.
• Seattle had other places to check out aquatic creatures in the '60s, including the Seattle Frozen Fish Aquarium, but these were privately owned.