(ABCNews)-- It was 10:50 p.m. on Sunday when a Detroit bus driver pulled up to one of his usual pick-up locations. As he opened the door, the person waiting at the bus stop threw bleach on his face and then ran away. The driver was rushed to the hospital and the suspect has not been caught. The bus was not equipped with a camera.
This brutal attack was the latest in a slew of attacks on bus drivers in Detroit that have, in recent weeks, included beatings, stabbings and even urine thrown at a driver.
In October, Detroit bus drivers staged a sick-out to protest dangerous working conditions, effectively shutting down the public bus system.
But the attacks aren't happening just in Detroit. They are occurring across the country and in Canada with an increasing frequency and brutality, according to the largest labor union representing transit and allied workers in the U.S. and Canada, the Amalgamated Transit Union (ATU).
"We've had many, many vicious assaults," ATU International President Larry Hanley told ABCNews.com today. "It is an ongoing and growing problem and the attacks appear to be getting more vicious."
Nationwide statistics on the attacks are hard to come by but Hanley estimates they are "absolutely in the hundreds, probably in the thousands."
New York City saw a 30 percent increase in attacks in 2012 and attacks in Philadelphia more than doubled from 2010 to 2011, according to the ATU.
"We've had this everywhere. It's universal," Hanley said. "Everywhere you go and in an alarming way it's been growing that bus drivers have been assaulted. As the economy got worse, attacks skyrocketed."
Hanley believes that many of the attacks are motivated by factors including the economy, transit services being cut, increases in fares and growing frustration in cities about lack of mobility.
"The economic downturn has hurt a great many people and there's a lot of anger out there," he said. "People don't run down to Wall Street and beat up brokers. They get on buses and beat up the drivers."
"People just driven over the edge in that moment and the bus driver is the most localized form or representative of government," Hanley said. "They come into your neighborhood defenseless, in uniform representing authority and then they have to tell you to pay your fare."
Bus drivers "live in the community," he said. "They work in the community. They see more people every day than any other public servant, but they get in these situations where they take abuse. There's irony there."
He also attributed the attacks to passengers coming from "all different life experiences," ranging from being thrown out of home after a fight with a spouse to drug addictions.
Actions are being taken both locally and nationally to try to improve conditions for drivers.
In Detroit, there used to be a police unit whose purpose was to patrol buses, but the city's economic struggles and dramatic cuts eliminated the unit.
Detroit Police Chief James Craig recently implemented several initiatives to protect drivers. The main initiative has two components -- uniformed officers who board the buses and ride for several blocks with a police car trailing behind and an investigative unit that puts undercover police officers on the buses.
"We're doing the best we can with the shortfall of manpower," Detroit Police Sgt. Michael Woody told ABCNews.com. "We allocate as much manpower as we can feasibly afford to put on these buses."
Woody said there are no definite or clear-cut motives for the attacks, but pointed out that bus drivers often have to deal with problems on their own and unarmed.
"Any situation that flares up on the bus, these drivers have to handle on their own and it leaves them open for retaliation," he said. "You know exactly when and where they're' going to be so it would be very easy to retaliate against them. These types of crimes are crimes of opportunity, crimes of randomness that have no real recordable value to them."
ATU's Hanley said "absolutely not enough" is currently being done in the U.S. and in Canada to protect drivers, but efforts are underway.
They are fighting to put cameras in all buses, to increase police presence, install protective shields and implement more safety training for drivers.
Though the shields can be put in buses after manufacturing, Hanley said most buses are not currently engineered for them so a driver's already cramped work stations can become claustrophobic and have ventilation problems.
Long-term solutions include new buses pre-engineered for the shields and doors on the driver's side.
"You wouldn't want to buy a car with no driver's door," Hanley said. "Think about yourself being cramped in the work station that drivers have with your back to two walls, a steering wheel in front of you and someone standing over you beating you."
"[There's] one way out and it's through the person beating your brains in," he said. "At least if the drivers could escape, we would have people with less serious injuries."