Three higher-ranking fire officers were present when firefighter Cheung Chun-wai died trying to rescue a man from a Shau Kei Wan sewer last year, the Coroner's Court heard yesterday. Senior Fireman Cheung, 40, collapsed after entering the sewer through a manhole in Smiling Shau Kei Wan Plaza, on Shau Kei Wan Road, in an attempt to rescue Lai Chaobao, 31, in July last year. Cheung was not equipped with breathing gear or even a rope when he went underground, the court heard. Principal fireman Hui Ping-fai said he was beside the manhole into which Lai fell, inspecting the situation. He later saw the leg of Cheung, who he believed entered the sewer from a nearby manhole. Mr Hui acknowledged he had not stopped firefighter Chui Ka-ming from going down the sewer in an effort to rescue Cheung after he collapsed. Chiu also collapsed later but was rescued. Senior station officer Tse Lai-yiu said that when he arrived at the scene, Cheung had not entered the sewer. 'I walked away from the sewer for five metres to make a call to the control centre. Because of this, my back was facing the manhole for a while,' Mr Tse said. He said when he heard screams from other firemen, Chiu had already entered the sewer. Probationary station officer Chan Hok-leung said on Tuesday he was with Mr Tse when the latter walked away with his back to the manhole. The Coroner's Court heard on Monday that Lai fell into the sewer after stepping on wet and greasy ground at 11.30pm on July 6. Cheung and Lai, who were later pulled out of the sewer by a police diver, were certified dead in Eastern Hospital at 1.30am on July 7. An autopsy blood test found the blood recovered from Cheung's lung contained 34 microgram of thiosulphate, a substance present after the inhalation of hydrogen sulphide. Normal blood should contain less than 0.3 micrograms of thiosulphate, the court heard. The inquest continues today.