The firefighter said the party included Juneteenth flags and fried chicken buckets and was in "one of the city’s most affluent communities.”
Seven adults and three children died after a fire tore through a northeastern Pennsylvania home on Friday.
"Why was the cat not arrested for attempted bank robbery?" asked one Facebook user.
“I mean, like, these are the same people who sign up to swarm hostage situations or run into burning buildings."
Firefighting can have lasting physical and mental consequences, and advocates argue it's time for the government to do more to help.
The president met with Western state governors as concerns grow over the risk of a historic fire season.
The off-duty firefighter, who has not been named by authorities, killed one colleague and wounded another in the Tuesday shooting, officials said.
Forecasters expected dry air and strong wind to pose a challenge for firefighters into the weekend.
The massive blaze started when a stunt intended to reveal the biological sex of an unborn baby went wrong.
“This bill that I’m about to sign will give those prisoners hope of actually getting a job in the profession that they’ve been trained,” Gov. Gavin Newsom said.