Eight people, including three firefighters, were injured early Saturday in a fire at a small apartment building on St. Paul’s West Side, authorities said.

A fire was reported before dawn in the building at 30 Baker St. W., near Humboldt High School, the Fire Department said in a series of tweets.

Firefighters quickly extinguished the blaze, which a resident had already tackled with a garden hose, they said.

Most of those injured suffered smoke inhalation and minor burns, the Fire Department said. One man was injured when he jumped from a third-floor window. Those hurt were evaluated at the scene by paramedics and taken to a hospital for further treatment.

The cause of the fire remains under investigation. The building was “too small to require fire alarms or sprinklers,” the Fire Department tweeted, adding, “Sprinklers would’ve made a huge difference.”