UCLA campus police received a phoned bomb threat targeting the university's Sunset Canyon Recreation Center late Wednesday, activating an emergency response that greeted individuals in nearby buildings with messaging that ranged from "stay indoors" to "evacuate."

The first emergency alert was issued shortly after 10 p.m. Wednesday, according to a report at latimes.com, followed by a second notice 30 minutes later that "the situation is still active." At 12:05 a.m. Thursday, the Twitter account @UCLA Housing sent the message "The Hill is in emergency. Please evacuate to Drake Stadium. Please retweet and share. More information will be provided as it comes in." According a screen capture on latimes.com, that message was retweeted at least 535 times. Five minutes later, @UCLA BruinAlert tweeted "Bomb threat at Sunset Recreation. Residents are requested to remain indoors unless otherwise instructed. Avoid the area until further notice."

Four bomb-sniffing dogs had searched the rec center, which police determined to be clear of explosives shortly before midnight. At 12:20, a BruinAlert informed individuals that they could return to their residence halls, which were occupied by a mix of students taking summer courses and children visiting the Westwood campus for sports camps. Drake Stadium, home to UCLA's soccer programs, is depicted being cleared in an individual's tweet posted at 1:56 a.m. Other evacuees were directed to a nearby tennis court, as alarms and flashing lights were triggered within some residence halls. In all, more than a dozen halls were affected.

Nineteen-year-old Lemoine Dillon, who was in Rieber Vista residence hall when alarms sounded, was among hundreds directed to the stadium. “It was really hectic because no one really knew what to do or where we were going,” Dillon told latimes.com.

The bomb threat came hours after the conclusion of the first orientation program for new UCLA students.

Paul Steinbach is Senior Editor of Athletic Business.