SAN FRANCISCO (CBS SF) — Firefighters in San Francisco were at the scene of a deadly house fire in the Presidio Heights neighborhood early Monday morning.

One man was dead and two people were injured, including a San Francisco firefighter.

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San Francisco Fire got the call reporting smoke and flames at a home on the 3800 block of Clay Street early Monday a few minutes before 1 a.m.

The front door of the home was sturdy and heavy and took the firefighters a bit longer than usual to force it open.

10 minutes after units arrived, the fire went to a second alarm. The fire started on the home’s second floor, and spread to the third floor.

Details are unclear at this point, but It looks like the majority of the damage was in a second story room that faces the street.

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There are at least two people who live there. One of the residents, an older man, was dead. The other victim went to the hospital with severe burns and was in critical condition, San Francisco Fire Department Lt. Jonathan Baxter said.

A firefighter also suffered burns when a crew opened a door and flames pushed towards them.

That injured firefighter was wearing full protective gear and was treated and released from the hospital.

Firefighters were pulling debris from the home to ensure the fire does not reignite as officials investigate the cause.

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The victims in the fire have not been identified pending notification of next of kin.