Preliminary investigation by the Department of Occupational Safety and Health (DOSH) is focusing on the form work failure which is believed to be the cause of the collapse of the interchange ramp of the Penang Second Bridge Thursday.

Its Penang Director, Mohd Anuar Embi said the main factor for the incident could be the failure of the form work.

"I do not rule out other possibilities but our early investigation is on the support of form work," he told reporters after inspecting the site here today.

He said he did not rule out that the incident could be due to improper installation or maintenance of the support form work.

"All this must be carried out accodring to good engineering practice in order to avoid any untoward incident," he said.

He added that the investigation could go up to two months depending on the complication.

The interchange ramp of the Penang Second Bridge which is under construction at Lebuhraya Tun Dr Lim Chong Eu, here collapsed at about 6.40 pm Thursday.

It affected the concrete ramp and steel girders in Package 3A at the exit passage from the bridge to the highway on the island part.

Three people were hurt and two of the victims were construction workers Slamat, 36, from Indonesia and Tin Maung Iwin, 39, from Myanmar.

The other person hurt was Thilasheni Rajendran, 24, who was hit by falling debris on the hand.

Thilasheni who was driving managed to stop her car about two metres away from the scene of the collapse.

Her friend Gajashaantini Gajanujan, 24, who also was in the car escaped unhurt.