It may or may not have been the first time an attempted illegal border crossing was live-tweeted.

It very likely was the first time such an event was live-tweeted by a sitting U.S. senator.

During a visit to the border town of Nogales, Ariz., Sen. John McCain, along with three other senators, watched a woman successfully jump the border fence, getting a firsthand look at one of the main issues surrounding immigration reform: how to secure the border.

McCain sent out a Twitter picture Wednesday following the event, saying:

McCain had invited Sens. Chuck Schumer, D-N.Y., Michael Bennet, D-Colo., and Jeff Flake, R-Ariz., to visit Arizona as Congress is working to craft new immigration reform legislation. The four senators are part of the bipartisan "Gang of Eight" leading the legislative effort.

McCain then posted another tweet, saying: