1

在

zài

to exist; to be alive (of sb or sth) to be (located) at (used before a verb to indicate an action in progress)

2

夜間

yèjiān

nighttime evening or night (e.g. classes)

3

發生

fāshēng

to happen; to occur; to take place; to break out

=4

了

le

(completed action marker) (modal particle indicating change of state, situation now) (modal particle intensifying preceding clause)

=4

了

liǎo

to finish (used with 得 dé or 不 bù after a verb to express (im)possibility, as in 忘不了 wàngbuliǎo "cannot forget") (literary) (usually followed by a negative such as 無 wú or 不 bù) completely (not); entirely (not); (not) in the least to understand clearly (variant of 瞭 liǎo)

=4

了

liǎo

(of eyes) bright clear-sighted to understand clearly

=4

了

liào

unofficial variant of 瞭 liào

5

火災

huǒzāi

serious fire (in a city or a forest etc)