Rene Padilla had hoped to spend a carefree day at the beach with his two pre-teen daughters before the new school year.

Instead, the girls watched helplessly as the 35-year-old construction worker slipped beneath the choppy waters at the 31st Street Beach and drowned Thursday afternoon.

“They are distraught,” said Roberto Spagnolo, Padilla’s work partner, speaking Friday about his friend’s family. “They are taking it very hard. ... They don’t know what to do. They are looking for guidance.”

Padilla died after trying to rescue his 12-year-old daughter when she was swept into Lake Michigan Thursday, Spagnolo said. Just before she fell into the lake, the girl was standing on the breakwater in the 700 block of East 31st Drive, Chicago police said. Padilla, police said, jumped in to try to save her.

“He loved them to death,” Spagnolo said of Padilla’s affection for his kids. “They were his girls. They loved Dad, and Dad loved them back.”

Chicago Park District lifeguards pulled both Padilla and his daughter out of the water.

“They were already performing CPR when we got to the scene,” Chicago Fire Department spokesman Larry Langford said. “Our medics took over the CPR from the lifeguard and performed advanced life support.”

Padilla, who lived with his family in Blue Island, didn’t respond. He was taken in critical condition to Mercy Hospital, where he was later pronounced dead. The daughter did not need treatment, officials said.

“He’s a very capable guy. I wouldn’t think anything like that would happen to him,” Spagnolo said of the man with whom he’d worked construction jobs for nine years. “He’s very strong and very agile.”

Padilla rarely took a day off from work, Spagnolo said.

“The girls were always begging Dad to take them to the beach,” he said.

Spagnolo said his friend was originally from Mexico, where his mother still lives.

“He still sends money to Mom,” Spagnolo said.