Both Queens-bound and Bronx-bound lanes reopened on the Throgs Neck Bridge by Friday evening, after a fire blocked traffic for most of the workday and injured five people.

The fire broke out shortly after 5 a.m.

The Queens-bound lanes reopened around 1 p.m. and two Bronx-bound lanes reopened around 6:30 p.m.

By late Friday, no commercial vehicles were allowed on northbound lanes.

Metropolitan Transportation Authority officials said construction materials on a scaffold hanging below the bridge caught fire. Subcontractors working on an ongoing deck replacement project had been working with welding equipment until 4 a.m. Friday.

It took more than seven hours and 140 firefighters to bring the flames under control.

Two firemen and three MTA officials received minor injuries, but none were hospitalized.

"They quickly got units in place and were able to put water on the fire and knock it down," explained FDNY Deputy Chief Bob Maynes. "And then extended operations started, where we actually had to put firefighters down into the scaffold area, which was a dangerous situation, and eventually we had to pull people back due to fire damage on the scaffolding."

As of late Friday, there appeared to be no problems with the structural integrity. The Bridge and Tunnel Authority was investigating the cause of the fire.

"The most thing important thing is safety," said MTA Executive Director Helena Williams. "We will be very conscience of making safe repairs to the bridge. We'll do that with all diligence."

MTA officials said Friday that there was no schedule for repairs.

The closures made a mess of the morning rush. Traffic was diverted to the Bronx Whitestone and Robert F. Kennedy-Triborough Bridges.

"I've been waiting probably an hour," said one driver. "I probably can't afford to wait, but I'm not going to sit in traffic somewhere else."

"It would cost at least two hours of delay to get to work," said another. "We are plumbers so to get to work we're going to have to find another way."

The road closure meant major detours for family members attending a "welcome home" ceremony for Maritime College students returning after two months at sea. The college campus and pier sit just under the Throgs Neck in Silver Beach.

"Came in from Staten Island, had to take the Triborough, it took an hour more, at least," said a parent. "I had to be here; my son's graduating."

According to the MTA, the 48-year-old bridge carries an average of 112,000 vehicles daily.