Timeline of Saturday’s gunman hoax incident, from report to the all-clear

7:28 a.m.

Cambridge Police receive report of male with a “large firearm and wearing body armor.” MIT Police is notified.

7:30 a.m.

Cambridge and MIT Police respond to 77 Massachusetts Avenue.

7:35 a.m.

Cambridge Police tweet “Report of possible person with gun on Mass Ave in #CambMA”

7:35 a.m.

State police begin shutting off traffic on Mass Ave between Vassar Street and Memorial Drive.

7:43 a.m.

Police have locked down the area around MIT’s Main Group Buildings (although there were still reports of students and staff in the buildings later).

8:37 a.m.

Someone at the MIT Police’s control center asked whether he should contact the Security and Emergency Management Office (SEMO) to send out an alert asking people to stay out of the Main Group (MIT’s central buildings).

8:47 a.m.

MIT’s emergency information website, emergency.mit.net, is updated. “This morning information was received from Cambridge Police that there was a person with a long rifle and body armor in the Main Group Building of MIT. Multiple law enforcement agencies have responded, please stay clear of the area until the authorities can confirm that it is safe to enter. More to follow.”

8:51 a.m.

MIT’s emergency alert sends a text message. “Multiple law enforcement agencies on campus in response to a report of a person with a gun on campus, further info on the Emergency Web Page.”

9:10 a.m.

A second text message is sent out. “Multiple law enforcement agencies on campus in response to a report of a person with a gun on campus. Stay indoors and shelter in place and report suspicious activity to the campus police dispatch dial 100.”

9:22 a.m.

MIT Alert sends out an email to all-campus@mit.edu saying “This morning information was received by Cambridge Police that there was a person with a long rifle and body armor in the Main Group Building of MIT. Multiple law enforcement agencies have responded, stay indoors and shelter in place and report suspicious activity to the campus police dispatch dial 100. More updates to follow on emergency.mit.net.

9:30 a.m.

A third text message says “Continue to shelter in place, report suspicious activity by cell phone to MIT Police.”

Around 10:00 a.m.

Cambridge Police start to clear the scene.

10:19 a.m.

Cambridge Police tweet “Scene is clear. Call unfounded. No threat to public safety in #CambMA #MIT”

10:46 a.m.

MIT alert sends a text message saying “Cambridge Police have issued all-clear. MIT returning to normal operation. MIT PD will monitor campus.”