Fire
noun
A fire matter is a fire, as in the destructive burning of something. There's a fire! Run, run away! 火事 is often used for when houses or other buildings are on fire. If you hear someone shout 火事だ, it's probably time to get out of wherever you are.
かじ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
火事だ！！
Fire!!
火事にならないよう、タバコの火には気をつけて下さいね。
Please be careful with lit cigarettes so as not to cause a fire.
昨日、３丁目で火事があったそうです。死者やケガ人は出ませんでした。
It seems there was a fire at 3-chome yesterday. There were no deaths or injuries.