Commuters have been warned to prepare for extensive delays during the Monday morning peak hour rush, with fears the train line to Sydney Airport could remain closed after a crane crashed into a block of Wolli Creek apartments on Sunday morning.

The crane is believed to have been in the process of being set up when it fell backwards, slamming into the penthouse apartment and causing structural damage to the upper levels and roof of the building.

A Wolli Creek resident described how another crane was forced to rescue the stranded driver.

"The man from the white crane (which crashed), he jumped over to the rooftop of the penthouse. So they (the second crane) went to the rooftop and picked him up," Felicia Nguyen said.