(CNN) - There have been a number of fatal commuter train crashes through the years. Here's a list of the deadliest crashes since 2000:
September 12, 2008: Metrolink commuter train
Casualties: 25 killed; more than 100 injured
Where: Chatsworth, California, near Los Angeles
What: A Metrolink commuter train and a Union Pacific freight train collided head-on in the late afternoon. The Metrolink's locomotive and one of its three passenger cars derailed; two of the freight train's locomotives and 10 of its 17 cars derailed.
Why: The National Transportation Safety Board determined that the Metrolink engineer -- among those killed in the wreck -- was distracted while he was text messaging someone on a phone, and that he therefore failed to stop his train at a red signal. Metrolink already had prohibited its engineers from using wireless devices while operating trains. The NTSB said the crash could have been avoided if the Metrolink train had had positive train control technology, which combines GPS and other technology to monitor trains and stop them from colliding, derailing or speeding.
As a result: The NTSB recommended that all rail companies install cameras and audio recorders at the controls so bosses could occasionally review whether their engineers were breaking cell phone rules. Congress ordered the nation's railroads to adopt positive train control by December 2015.
January 26, 2005: Metrolink commuter train
Casualties: 11 killed
Where: Glendale, California, near Los Angeles
What: A Metrolink commuter train struck an unoccupied Jeep Cherokee that a man had parked on the railroad tracks. The southbound train derailed, ran into a northbound Metrolink train and then crashed into a Union Pacific train that was parked nearby. Until 2008 (above), this would be Metrolink's deadliest crash.
Why: Prosecutors accused Juan Manuel Alvarez of parking the vehicle on the tracks, intending to kill commuters, so he could get attention from his estranged wife, the Los Angeles Times reported. Defense attorneys claimed Alvarez parked the vehicle there intending to commit suicide, but changed his mind and exited the vehicle before the train arrived, according to the Los Angeles Times.
As a result: Alvarez was convicted of murder in 2008 and sentenced to life in prison.
June 22, 2009: WMATA commuter train
Casualties: Nine killed; dozens injured
What: One Washington Metropolitan Area Transit Authority commuter train (Train 112) struck the rear of another (Train 214) that was stopped near the Red Line's Fort Totten station during rush hour about 5 p.m. The rear car of Train 214 telescoped about 63 feet into the lead car of Train 112, the NTSB said. All nine people who died were on Train 112, and that included 112's operator.
Why: A track circuit component that is supposed to detect trains failed in the area where Train 214 was stopped -- meaning Train 214 was invisible to Washington Metro's automatic train control system. Since Train 214 was essentially invisible, the system commanded Train 112 to keep going right into the back of 214, the NTSB found. The NTSB said the crash would have been avoided had Washington Metro properly tested its system.
As a result: The NTSB made a number of safety oversight and equipment inspection recommendations.
May 12, 2015: Amtrak
Casualties: Eight killed; more than 200 others injured
What: An Amtrak train, headed to New York from Washington with 238 passengers and five crew members, derailed. Video showed the train was speeding up as it approached a curve, just moments before its derailment.
Why: The NTSB determined the train's engineer, Brandon Bostian, was distracted prior to the crash by radio chatter from other train operators. Bostian's train approached the curve -- which had a suggested speed of 50 mph -- at 106 mph.
As a result: The NTSB made recommendations to the Federal Railroad Administration for recurrent training for train engineers to help them better manage the necessary tasks when in control of a train.
June 24, 2011: Amtrak
Casualties: Six killed; 16 injured
Where: A desert in Churchill County, Nevada
What: A heavy commercial truck struck an Amtrak passenger train at a crossing, killing the truck driver, the train conductor and four train passengers. The train was headed from Chicago to Emeryville, California.
Why: The NTSB said the driver was inattentive, asserting that although the crossing signals were active when the truck was nearly a half-mile away, the driver didn't start braking until his truck was 300 feet from the crossing. The NTSB also said nine of the truck's 16 brakes were out of adjustment or inoperative.
As a result: The NTSB made 20 safety recommendations to a number of parties, including the truck driver's employer.
February 3, 2015: Metro-North
Casualties: Six killed; more than a dozen injured
Where: Valhalla, New York
What: A Metro-North passenger train struck an SUV at a crossing at 6:26 p.m. Witnesses said the SUV was stopped in the crossing when the crossing gates came down, striking the rear of the SUV, according to a preliminary NTSB report. The SUV driver got out, looked at the back of the SUV, re-entered the vehicle, drove forward and was struck by the train, the preliminary report says. The train's engineer applied emergency brakes, but the train, though it had been going just under a 60-mph limit, did not stop in time, the NTSB said. Killed were five train passengers and the SUV driver.
Why: The NTSB is investigating.
April 18, 2002: Amtrak
Casualties: Four killed; 142 injured, including 36 seriously
Where: Near Crescent City, Florida
What: An Amtrak train carrying 446 people derailed on a left-hand curve of a CSX-owned track. Twenty-one of the train's 40 cars were off the rail.
Why: The NTSB said the track buckled, blaming what it said was CSX's inadequate track resurfacing operations. The buckle happened where a CSX resurfacing crew had been working. According to the NTSB, the crew had shored up the track after a substantial drop in temperature only to see it expand and buckle a few days later when temperatures rose.
As a result: The NTSB recommended, among other things, that CSX start a quality-control program for its track surfacing workers.
December 1, 2013: Metro-North
Casualties: Four killed; at least 61 others injured
Where: Bronx, New York
What: A Metro-North passenger train, heading from Poughkeepsie to Manhattan's Grand Central Terminal, derailed at a left-hand curve. The lead car came to rest inches from water at the intersection of the Hudson and Harlem rivers.
Why: The NTSB said the train was traveling at 82 mph when it derailed at a curve where the speed limit was 30 mph. The train was going over the speed limit because the engineer had fallen asleep "due to undiagnosed severe obstructive sleep apnea exacerbated by a recent circadian rhythm shift required by his work schedule," the NTSB said.
As a result: The NTSB recommended, among other things, the installation of speed restriction signs letting engineers know they are approaching a point where speed must be reduced.
December 18, 2017: Amtrak
Casualties: Three killed; more than 100 others injured
Where: DuPont, Washington
What: An Amtrak passenger train derailed and hurled 13 of its 14 cars off both sides of an overpass and onto rush hour traffic below. The Amtrak Cascades 501 train was carrying 86 people as it made its inaugural journey on a new service route from Seattle to Portland when it derailed.
Why: The Amtrak engineer told investigators with the National Transportation Safety Board that he mistook a signal and braked moments before the crash. Investigators said the train careened around a curve at almost three times the speed limit. The train was traveling 80 mph in a 30-mph zone, NTSB member T. Bella Dinh-Zarr said.
As a result: The incident is still under investigation.
February 4, 2018: Amtrak
Casualties: Two killed, more than 100 injured and transported to local hospitals
Where: Cayce, South Carolina
What: An Amtrak passenger train collided with a CSX freight train. The crash occurred at about 2:35 a.m. The train was traveling between New York and Miami with 147 people aboard, including the crew. The CSX freight train was stationary on the tracks.
Why: Officials don't yet know for certain.
As a result: The incident is under investigation.
April 3, 2016: Amtrak
Casualties: Two killed; 41 others injured
Where: Chester, Pennsylvania
What: An Amtrak train crashed into a backhoe that was on the tracks, killing two Amtrak construction workers. The train, traveling from New York to Savannah, Georgia, was carrying 337 passengers and seven crew members. The impact caused the lead engine of the train to derail.
Why: A preliminary report from the NTSB indicates the two construction workers, doing maintenance work, were on the wrong line when they were struck and killed.