The fatality was identified by the Manila Police District as Zaldy dela Torre, a 35-year-old welder employed by contractor Amsteel Structures Inc.
Initial police reports showed that Dela Torre was attaching a "fire catch" to a scaffolding at an elevated section of the bridge, as a safety measure to prevent welding sparks from falling on people or vehicles on the ground, when he lost his balance and fell, hitting the pavement head first.
The accident happened around 2:30 p.m. Dela Torre was rushed to Philippine General Hospital, where he was declared dead on arrival.
An investigation showed that Dela Torre was last seen wearing a safety harness but that he apparently failed to attach this to any of the safety cables hanging from the bridge.
Police said the victim suffered a fracture in the skull as well as injuries in the body.
Meanwhile, after almost three months since the repairs started, the bridge was partially reopened Monday but authorities limited entry to light vehicles.
Reynaldo Tagudando, director of the Department of Public Works and Highways (DPWH) for the National Capital Region, said trucks and heavy vehicles would be allowed once full rehabilitation is achieved in September.
For now, just two out of the three lanes on both directions are open to traffic, he said.
Tagudando said some aspects of the rehab project were yet to be finished, like the post-tensioning of the beams and the installation of dampers to make the structure more stable.
The DPWH has set aside P447.95 million for the upgrade of the bridge, which last saw major repairs in 1957.
The 139-meter-long structure on the Pasig River was also raised by 70 cm to allow more headroom for barges and other vessels.