The main level of a house undergoing construction in Weston collapsed on Friday evening.

The accident occurred at a property along William Street between Merrill Avenue and Pine Street at 7:30 p.m.

The first floor fell into the basement of the house, Toronto fire said.

No one was in the home at the time of the incident and no injuries were reported.

A building inspector has been called in to assist with the investigation.

The cause of the collapse is not yet known.