Donald Trump Accidentally Invokes '7-11' When Talking About '9-11'

The GOP front-runner invoked the wrong date during an event in Buffalo.

There is "nothing nicer than [the] U.S.A. I think what I want to do is I want to talk just for a second. I wrote this out and it’s very close to my heart,” the Republican front-runner said at an event here in Buffalo.

He began to invoke the attacks on the World Trade Center, describing the courage he saw there. There was just one small problem -- he mixed up the date.

"Because I was down there, and I watched our police and our firemen down on 7/11, down at the World Trade Center, right after it came down and I saw the greatest people I have ever seen in action," Trump said.

The attacks occurred on Sept. 11, 2001.

"Tomorrow we are gonna show Ted Cruz, who hates New York, hates New York. ... You see the way he talked about us, and New York values. Here is the man that turned down [Hurricane] Sandy money for this state,” Trump said.

Trump suggested that Cruz’s night on Tuesday would not end happily.

“By the way, wouldn’t it be interesting if Ted Cruz came in third tomorrow? Won’t that be interesting?” Trump asked.

He added, "No New Yorker can vote for Ted Cruz and no New Yorker can vote for [Ohio Gov. John] Kasich when he was one that approved NAFTA.”

Trump is expected to handily win his home state, which would provide a crucial rebound after delegate losses in Colorado and Wyoming.

The crowd inside the venue in Buffalo was solidly for him, despite a protest that marred his introduction. Twenty-one people were ejected from the event after protesting inside, according to Buffalo Police. Six arrests were made outside as demonstrators protested the event, police said.