Three people were killed and 16 injured when an MTA bus and a charter bus crashed in Flushing on Monday morning, shortly after 6 a.m. The collision, between a Q20 bus and a private Dahlia Travel and Tours bus at the intersection of Northern Boulevard and Main Street, sent the Dahlia bus crashing into a Kennedy Fried Chicken and other businesses along Northern Boulevard, police told DNAinfo. [Scroll down for updates, including security camera video of the crash.]

#FDNY members on scene of a serious accident involving two buses at 136-04 Northern Blvd #Queens pic.twitter.com/CPVdXDCmPn — FDNY (@FDNY) September 18, 2017

MTA Chairman Joe Lhota spoke to reporters on the scene Monday morning, stressing that at least one party involved in the crash sped dangerously.

"As we’ve observed these buses spun around, that requires an enormous amount of speed," Lhota said.

A source told NY1 that the Dahlia bus driver ran a red light, but at a press conference at the scene this morning, Mayor Bill de Blasio and NYPD officials said the investigation was too preliminary to confirm details about the cause of the crash.

An NYPD spokesperson said the private bus driver was killed as a result of the crash. One pedestrian on the sidewalk was pinned under a bus and killed, and one MTA bus passenger was pronounced dead at the scene. Of the sixteen injured, "several... are critical and are fighting for their lives right now," Mayor de Blasio told reporters.

The MTA bus driver, a ten-year veteran, sustained minor injuries and was being questioned on the scene Monday morning.

Officials said the Dahlia bus driver was headed east on Northern Boulevard and the MTA bus driver was on Main Street, making a right turn onto Northern Boulevard when Dahlia driver crashed into it. A fire started in the Kennedy Fried Chicken after the private bus crashed into it.

Dahlia has been cited for unsafe driving multiple times by federal regulators, and has been sued multiple times. DNAInfo reports that last year, a bus owned by Dahlia overturned while traveling to a Connecticut casino, injuring 30 people.

Since 2009, 33 drivers have been injured at the intersection of Northern Boulevard and Main Street, according to Vision Zero data. Five of those injuries occurred in 2017.

"Of course we’ll look at the intersection itself to see if there’s anything else that we have to do to improve the situation," Mayor de Blasio said.

Major Bus Ax in Queens at Northern Blvd & Main St.

17 injured. 7 critical, 10 stable.

More to come....@ABC7NY pic.twitter.com/KRVPfHGoLC — Dray Clark (@DrayClarkABC7) September 18, 2017 PLEASE AVOID MAIN ST & NORTHERN BLVD DUE TO A VERY SERIOUS COLLISION INVOLVING 2 BUSES. **HEAVY TRAFFIC DELAYS** pic.twitter.com/zvtu9l20eF — NYPD 109th Precinct (@NYPD109Pct) September 18, 2017

Update: Security camera footage of the horrifying crash shows the MTA bus turning and the Dahlia tour bus slamming into the MTA bus' rear—forcing the city bus to spin around—and into the building on the corner.

Just in NEW video showing the second the buses collided in #queens . 3 killed, more than a dozen injured More soon @ABC7NY pic.twitter.com/pWwFrgWS86 — Kemberly Richardson (@kemrichardson7) September 18, 2017

Update 4:33 p.m.: Following the crash, photographs of the private bus's speedometer showed the needle stuck at 60 mph. The speed limit on Northern Boulevard is 30 mph.

This story has been updated with preliminary information from the NYPD, quotes from Mayor de Blasio and Chairman Lhota, and security camera video.

Additional reporting by Emma Whitford.