Re: WWYCD: Lost in a world without Supers; 9/11/2001
Terminus would go straight to Washington DC, and walk in to the White House. He would be careful not to hurt anyone too badly, but he would see the man in charge, and tell him exactly what is going to happen.
After that, ultimately, he would consider the job done. He can't fly, and has no capacity to stop a plane - he would have to hope that the authorities, forewarned, can deal with it.
(As to the "how do you know?" part - he just walked through the White House security cordon without breaking a sweat. If that doesn't make them take him seriously, nothing will.)
If it was the team - Terminus would still do as the above, but he'd station Trawler in Boston and Avatar outside Washington Airport first, with Zero keeping the team mindlinked, and Miss Chaos in reserve to get everybody out if things went badly. If the authorities failed to act, Trawler and Avatar would shut down the airports rather than allow the events to proceed.