PORT ST. LUCIE, Fla. >> A 21-year-old pre-med student was eating lunch when he heard a commotion outside the Hurricane Grill & Wings. He ran outside and saw a silver Lincoln half-submerged in the lake.

Two other men — one in the restaurant and another walking by — also saw the car and, along with Alton Brieske, jumped in the water, smashed out a window and pulled 92-year-old Salvtore Mancuso to safety. Police said he was taken to a hospital in critical condition.

Investigators don’t know what caused Mancuso to drive into the lake less than a half-mile from his home around 1 p.m. Wednesday.

"I was walking and the next thing I know there is a car going over the median, in the curb and straight into the lake," said Nikolas Guevara, 21.

He was joined by Brieske and Mike Markisello, who was also ordering lunch inside the wings restaurant.

The three strangers struggled to rescue Mancuso, Scripps Treasure Coast Newspapers reported.

"The water had to be 8 to 10 feet deep and the car was 20 to 30 feet off the shore," said Brieske, who was home from Florida Atlantic University for the holiday break.

"It was extremely cold in the water," Guevara said.

The men tried unsuccessfully to open the car door and break the window. A bystander tossed them a hammer and they finally shattered a side window. Brieske climbed in and pulled Mancuso to shore. There, Brieske, who said he wants to be an ER doctor someday, performed CPR until emergency officials arrived.

Port St. Lucie Master Sgt. Frank Sabol said Mancuso was in critical condition Thursday.

None of the men consider themselves as heroes.

"Just an average person trying to do a good deed," Guevara said.

"I guess I was just (Mancuso’s) guardian angel," Brieske added.

After Mancuso was taken to the hospital, Brieske and Markisello returned to the restaurant. Brieske ordered ancho chili lime chicken wings. Markisello ordered a hamburger and fries. This time, it was on the house.