Metrolinx, the TTC and the Greater Toronto Airports Authority were all made aware of a threat prior to a terrorism suspect being killed in a police takedown in Strathroy on Wednesday.

TTC spokesperson Brad Ross tells CP24 that officials were “made aware of a terror threat investigation” on Wednesday morning but were not provided with any specific details beyond that.

Ross said that in response TTC CEO Andy Byford spoke with Police Chief Mark Saunders and formulated an “internal plan.”

The TTC then issued a “See something, say something” vigilance notice to all staff, as it does when significant terror attacks occur internationally or when its “advised of threats closer to home,” Ross said.

“We don’t have any information that there was a threat made to the system,” Ross told CP24 on Thursday morning. “We don’t have that information whatsoever; just that there was a threat to the city in some shape or form.”

Ross said that the directive issued to staff didn’t specifically state that there was an active investigation and merely reminded them to be vigilant. ”

Ross said that notices like the one issued on Wednesday are put out “fairly routinely” in the wake of terror attacks.

“The actions we took were ones of just being extra vigilant,” he said.

Metrolinx was also advised of an unspecified threat on Wednesday.

According to spokesperson Anne Marie Aikins, the transit agency raised its level of vigilance in response and “worked closely with national, provincial and local security and police services.”

“In response we did what we normally do which is increase our vigilance and remind our staff about our own processes that we have in place to ensure public safety,” Aikins told CP24.

Aikins said she does not have anything “specific about the location” of the threat, however she noted that “transit safety officers worked closely” with police to ensure public safety.

Aikins also said that there were already additional transit safety officers on hand at Union Station due to platform changes resulting from ongoing renovations to the busy transit hub.

Meanwhile, the Greater Toronto Airports Authority, which looks after Pearson International Airport, was also notified of a “non-specific threat” on Wednesday, according to spokesperson Siobhan Desroches.

As a result, Desroches said that the GTAA “worked with partners responsible for airport security to enhance our security posture.”

Toronto Mayor John Tory said city staff and police responded immediately when word of a possible threat came on Wednesday.

"Toronto Police and other City agencies demonstrated vigilance and worked with the RCMP and our jurisdictional partners to ensure necessary precautions were taken. I have spoken with Chief Saunders, who will continue to work collaboratively with our law enforcement partners to keep the people of Toronto safe."

Aaron Driver, a known Islamic State sympathizer, was killed inside a home in Strathroy on Wednesday following an interaction with police.

According to an internal government memo obtained by CTV News, Driver had allegedly planned to use an IED to carry out a suicide bombing mission in a public area.

The memo identified airports, bus stations, train stations, waterfront areas and rush hour traffic as potential targets.

The RCMP has not said what city was the alleged target of the plot.

Driver had been under a court order not to associate with any terrorist organization at the time of his death, according to a copy of his peace bond obtained by CTV London.

He was also banned from owning a cell phone, computer, tablet or any other wireless device. He was prohibited from positing on any social media site.

He was not allowed to possess any symbol or logo of ISIS or Al Qaida in Syria.

The RCMP said that it will hold a news conference at 1 p.m. this afternoon in Ottawa to provide further details on the case.