A student, Tony Murillo, recorded some of the lecture on video as Barrese wrote on a chalkboard and stepped through flood water on the classroom floor.

"(The professor) casually continued on his lecture despite a tornado advisory and serious flooding in the room," said Murillo. "His actions are a testament to the dedication of UCSD's faculty."

"He did end up letting us out early," Murillo said.

Watch the video below.