Three people were injured Wednesday — one critically — following an early-morning fire at a San Francisco home.

Bay City news reports that callers to 911 reported the blaze at 1:55 a.m. Wednesday.

When firefighters arrived at the burning home, which is located at 376 Harvard Street, near McLaren Park, "they saw a fire from the front window on the second floor of a two-story apartment building and observed a 17-year-old boy fleeing the burning structure," the Chron reports.

The teen told firefighters that his parents were still inside the home, offering specific directions on where to find them inside the house. Firefighters used those directions to rescue a woman, who KRON 4 reports was still conscious. They also pulled a man from the blaze, who "was unconscious and firefighters attempted to resuscitate him."

The fire was under control by 2:12 a.m., the SFFD announced via tweet.

All three of the victims were transported to an area hospital for treatment, the teen and woman with moderate burns, the man with critical injuries. An update on their conditions were not available as of publication time.

Three other residents of the building were also displaced in the fire. It's unclear if they were home at the time of the incident.

According to the San Francisco Fire Department, the cause of the blaze is still under investigation.