An estimated 800,000 people gathered on the Golden Gate Bridge on May 24, 1987, to celebrate its 50th anniversary.

The crowd was so dense that officials had to close the bridge and allow only pedestrians. The weight of the crowd caused the bridge’s suspension deck to flatten, eliminating the slight upward arch that normally characterizes the roadway. All 419,000 tons groaned and swayed in the wind. While the bridge was structurally sound and did not suffer any damage, the change in shape was alarming to many pedestrians. Engineers described it as a “once-in-a-lifetime event,” but stressed that there was no real danger.