The horrific attacks in Belgium on Tuesday killed more than 30 people and injured at least 260 others. Here is a timeline of how and when the tragic events unfolded:
7:55 a.m. (3: 55 a.m. ET): CCTV footage shows the suspected attackers exiting a taxi and pushing luggage trolleys through the Zaventem international airport outside Brussels.
7:58 a.m. (3:58 a.m. ET): Gunfire reportedly heard in the departures terminal followed by an explosion. As passengers started running, a second explosion hits.
8:20 a.m. (4:20 a.m. ET): As emergency services began the rescue operation, Belgian authorities stopped rail transport to the airport and closed roads.
8:40 a.m (4:40 a.m. ET): The airport confirmed the explosions and urged people to stay away from the area. A crisis cell met at Belgium's interior ministry.
9:10 a.m (5:10 a.m. ET): A blast was reported on a train at the Maalbeek metro subway station, near the headquarters of the European Commission.
9:27 a.m. (5:27 a.m. ET): The entire Brussels metro system was closed. At around the same time, French President Francois Hollande held an emergency meeting with ministers.
10 a.m. (6 a.m. ET): Brussels' entire public transport system — including streetcars, buses and trains — was shut down. The Belgian Crisis Centre tweeted: "Stay where you are."
10:13 a.m. (6:13 a.m. ET): London's Gatwick Airport announced it was increasing security.
10:35 a.m. (6:25 a.m. ET): The Eurostar train service suspended service to and from Brussels Midi station. The rail service links London with Paris and Brussels via the Channel Tunnel.
11:15 a.m. (7:15 a.m. ET): President Obama condemned the "outrageous attacks."
11:20 (7:20 a.m. ET): France deployed an extra 1,600 police officers to its borders and placed some on public transport.
11:25 a.m. (7:25 a.m. ET): Police and soldiers reinforced security around Belgium's nuclear power plants.
11:30 a.m (7:30 a.m. ET): Belgium deployed an extra 225 troops to Brussels.
11:43 a.m (7:43 a.m. ET): Belgian Prime Minister Charles Michel condemned the "blind violent and cowardly" attacks.
11:46 a.m (7:46 a.m.ET): Paris mayor Anne Hidalgo announced that the Eiffel Tower would be lit in Belgium's national colors — red, black and yellow.
11:58 a.m. (7:58 a.m. ET): U.S. European Command confirmed an American Air Force officer, his wife and four children were injured in the attack at the Brussels airport. They did not name the family.
12:20 p.m. (8:20 a.m. ET): Facebook activated its "safety check" system to help people check on their friends and loved ones.
12:30 p.m. (8:30 a.m. ET): Russian Foreign Ministry spokeswoman Maria Zakharova said the West's politics of "double standards" have led to terrorist attacks and that frozen diplomatic relations between NATO and Russia have slowed the fight with terrorism.
1 p.m. (9 a.m. ET): The European Union's top official, European Council President Donald Tusk, said he was appalled by the attacks.
1:15 p.m. (9:15 a.m. ET): The U.S. Embassy in Brussels recommended that Americans in Belgium stay where they are and avoid public transportation.
1:21 p.m. (10:21 a.m. ET): Manish Kalghatgi, a spokesman in Mumbai for Jet Airways, told The New York Times that two of the Indian carrier's cabin crew were among those injured in the Airport blasts.
3 p.m (11 a.m. ET): The Church of Jesus Christ of Latter Day Saints confirmed that three U.S. missionaries were injured in the attacks. Richard Norby, 66, Joseph Empey, 20, and Mason Wells, 19, were seriously injured when the blasts airport blasts occurred, they said in a statement.
3:20 p.m. (11:20 a.m. ET): ISIS claimed responsibility for the attacks, saying their members detonated suicide belts.
4 p.m. (12 p.m ET): Belgium's King Philippe said he and Queen Mathilde shared the pain of all those who had suffered because of the "cowardly and odious" attacks.
4:25 p.m. (12:25 p.m. ET): A Belgian official said that a third bomb had been deactivated at the airport.
4:45 p.m. (12:45 p.m. ET): Belgian authorities released surveillance camera images of the three suspects.
5:30 p.m. (1:30 p.m. ET): Eyewitnesses in the Schaerbeek district in north-east Brussels reported a major police operation around the train station. A cordon was put in place and anti-bomb vehicles were reportedly at the scene.
5:45 p.m. (1:45 p.m. ET): Belgian prosecutor Eric van der Sypt confirms that two suicide bombers died in the airport attack and that a third was being actively sought.
Wednesday March 23
9:55 a.m. (4:55 a.m. ET): French Prime Minister Manuel Valls urged the European parliament to move forward on authorizing a passenger name record covering the continent.
10:28 a.m. (5:28 a.m. ET): Brussels' Universite Saint Louis confirmed in a Facebook post that law student Leopold Hecht died in the attack on the Maalbeek subway station.
10:55 a.m. (5:55 a.m. ET): An assistant to Paris attack suspect Salah Abdeslam's lawyer, Sven Mary, confirmed that a judicial hearing had been postponed until March 24.
11:10 a.m. (6:10 a.m. ET): Pope Francis led thousands of people in silent prayer for the victims of the attacks in St Peter's Square.
12:20 p.m. (7:20 a.m. ET): The Belgian football federation has called off an international soccer friendly match against Portugal next week because of Tuesday's attacks in Brussels.
12:35 p.m. (7:35 a.m. ET): Belgians held a moment of silence to honor at least 31 people killed.
2:10 p.m. (9:20 a.m. ET): Belgian Federal prosecutor Frederic Van Leeuw identified one of the two suicide bombers as Ibrahim El Bakraoui, a 29-year-old Belgian born in Brussels. He said he was identified based on a fingerprint.
2:35 p.m. (9:35 a.m. ET): Van Leeuw said investigators have found 15 kilograms (33 pounds) of TATP explosives at the house which the suspects in the Brussels attacks left from for the airport, after being led there by a taxi driver.
This article originally appeared on NBCNews.com.