Good morning on this warming Thursday.

As the principal of P.S. 89 in Lower Manhattan, Veronica Najjar has guided her school through two terrorist attacks.

On Sept. 11, 2001, she was standing in the schoolyard, when she said she saw the first plane slam into the North Tower of the World Trade Center.

“I snapped into crisis mode,” said Ms. Najjar, 60, on Wednesday, thinking back to the day. She gathered students and teachers and led them a mile away to P.S. 3 in the West Village. “It was terrifying, but I was really calm.”

Sixteen years later, another deadly terrorist attack in Manhattan. On Tuesday afternoon, a man driving a truck killed 8 people and injured 12 others, before crashing into a school bus in front of the elementary school. The attack happened right after school let out, with some of the school’s 433 children outside in the schoolyard.