EAST BOSTON — Welcome to summer in the safest city in America.

By 4:23 p.m. Wednesday, transit police were on their way to Maverick Station, where about 15 teens had gathered inside the gates and were, as one scanner-tracker put it, "doing everything except waiting for the blue line." T Police, the post said, "slid over to restore order and remind everybody this ain't a rec center."

Three and a half hours later, two stops up the line at Orient Heights, a large fight broke out inside the station. One of the combatants pulled a gun. The crowd scattered. The gunman fled and was last seen heading toward Wood Island, the next stop inbound. Boston police "flooded" the area "in every direction," according to the same scanner account.

Whether the Maverick group migrated up the Blue Line and turned into the Orient Heights crowd, or whether the two were unrelated, isn't clear. Same line, same neighborhood, three and a half hours apart. Neither the MBTA Transit Police nor the Boston Police Department had issued public statements as of late Wednesday, and no arrest in the gun-pull had been publicly reported.

The scanner reports come from @StacoS, an account that tracks Boston public-safety radio traffic. MDN has not independently confirmed the gun-pull, the number of teens, or whether the two incidents were the same crowd.

For now, the immediate question is the gunman — and whether the afternoon at Maverick was the prelude.

This is a developing story.