I don’t know what was going on at the Santa Fe Railway’s La Grande railway station at 2nd St and Santa Fe Ave in downtown Los Angeles in this day in around circa 1910, but my guess is that someone famous and/or important was arriving and Angelenos turned out in droves to see him or her. Or maybe this is just the 1910 equivalent of going to the airport on Memorial Day long weekend.
With the opening of Union Station, the La Grande station was close in 1939, and was torn down in 1946. This building is now on that site. This image is from December 2020.