LOUISVILLE, Ky. (WDRB) - The school bus from which a Jefferson County Public Schools student fell on Tuesday is one of 400 buses involved in a lawsuit the district filed against a national bus manufacturer in 2013.

JCPS spokesman Ben Jackey confirmed that Bus No. 0829 was made by Navistar International Inc., the company the district
sued over engine and maintenance problems
, including an issue with "doors on the buses (that) have broken apart."

According to the district, two Breckinridge Metro High School students were involved in an altercation on the bus. After one of the students backed away from the fight, she fell down the bus's stairwell and out of the moving bus, which was in the process of making a turn.

The student suffered serious injuries and remains hospitalized.

The incident happened near the intersection of Breckinridge and Preston streets shortly after 2:20 p.m. on Tuesday.

Jackey said the doors on the bus were closed at the time and district officials are trying to determine how she fell out of the vehicle. He said the bus was equipped with a security camera, which caught the entire incident on tape.

"The door itself will be something that will be looked at as part of our investigation," Jackey said.

Jackey would not discuss details of what the video showed, saying it is part of an ongoing investigation.

Students are supposed to be seated and are not supposed to stand once they board a bus, he said.

According to the 2013 lawsuit, JCPS sued Navistar International Inc. -- the Delaware-based manufacturer of commercial trucks, buses, defense vehicles and engines -- as well as Bluegrass International, the Kentucky-based company that distributed them.

Officials say the district paid $32 million for the 396 school buses it purchased from Bluegrass International between 2005-2011. 

JCPS attorney Byron Leet told WDRB News Thursday the buses are "lemons."

"These buses have required much more maintenance than should be required," Leet said. "The district has had to spend a lot of money to fix and maintain them. They were initially under warranty, but in some cases, these buses have been fixed 10 or more times and the warranty no longer covers them."

The lawsuit is pending in Jefferson County Circuit Court. 

The main issue involves excessive wear on the engines, some of which have had to be replaced, Leet said.

The lawsuit also says JCPS "has experienced numerous problems with excessive and premature corrosion in the bodies of the buses. Rust damage to step wells, wheels, fuel tanks and bumpers on the buses is much more significant and appears after markedly shorter periods of operation than corrosion that appears in other buses in (the) fleet."

In addition: "many doors on the buses have broken apart and floor joists and sills on many buses have cracked and separated from the body-frame tie downs."

John Stovall, president of Teamsters Local 783, said these "particular buses international model from 2005 to 2010 have a history of popping open with very little force."

Despite the issues with the doors mentioned in the lawsuit, Leet said the district has properly maintained the buses.

"Because of the excessive preventive maintenance we have performed on these buses, there is no safety issue," he said.

Jackey said as of Thursday, the district has spent $2.3 million to make repairs to the buses mentioned in the lawsuit.

The district has about 1,250 buses, with about 960 that run daily routes. Officials estimate that about 63,000 of the district's 101,000 students ride the bus each day.

Stovall says fights on buses are a constant problem.

"That driver can't do it all and that's what they expect," he said. "They can come out of that ivory tower off Newburg Road and put their asses in seats and drive a bus."

Reporter Antoinette Konz can be reached at 585-0838 or @tkonz on Twitter.

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