A teacher's aide saved a choking second grader's life at Helen B. Duffield Elementary School in Ronkonkoma.

Seven-year-old Seren Mavruk began choking on her lunch last Wednesday. Her classmates, Logan Gelling and Autumn Slate noticed their friend was in trouble and called for Stella Tsimis, a teacher's aide, to help.

"I heard some children screaming, 'Seren is choking,' and I saw her running towards me and she was red, and she was kind of pointing to herself that she was struggling," Tsimis says.

Mavruk says she was choking so badly she was having trouble seeing.

"I could barely see so I saw this like grownup, so I ran over to her," Mavruk says.

Tsimis immediately turned the student around and did the Heimlich maneuver. With one thrust, everything became dislodged.

The teacher's aide learned how to perform the Heimlich maneuver during her time as a medical assistant at Northwell Health prior to joining the elementary school.

Tsimis says her medical training and maternal instincts kicked in when it mattered most.

"I just did what I would hope anyone would do and I'm glad I knew what to do," Tsimis says.

Mavruk says she considers Tsimis a hero because she saved her life.