Police are appealing for the public's assistance following an alleged deliberately lit fire in the grounds of Holy Spirit College.
The blaze ignited in dried grass in the grounds of the Bellambi school during Monday's heatwave and resulted in firefighters rushing to the scene.
"Whoever called it in had seen kids lighting a grass fire," Fire and Rescue NSW Duty Commander Greg Purvis said.
Despite the hot and windy conditions, firefighters were able to extinguish it before it spread.
"It was a couple of square meters, but they put it out pretty quickly," he said.
Nobody was injured during the incident, and a NSW Police spokeswoman has called on the public for information.
"Anyone with information is urged to contact Wollongong Police or Crime Stoppers on 1800 333 000," she said.
Also on Monday, firefighters were called to a gas bottle explosion at a Lake Heights home around 7pm.
The cylinder of argon gas, which is commonly used in welding, had been stored in the garage of a Lake Heights Road home.
"It appears it's just had a failure and fired like a bullet and hit the wall," Duty Commander Purvis said of the gas bottle. "It sounded a lot worse than what it was."
Nobody was injured during the explosion, but the side wall of the garage was left with significant damage.
At 2am on Tuesday, firefighters were called to a car fire at Wright Street in Fernhill. The car was destroyed by fire.
Late on Sunday, fire crews were called to a tipper truck blaze on Industrial Road at Unanderra. The fire was contained to the truck's cabin.
Sign up for our newsletter to stay up to date.