Beirut port officials placed under house arrest following deadly blasts

A series of arrests were made following Tuesday's devastating explosions in Beirut, Lebanon. At least 137 people were killed in a flash, more than 5,000 and some 300,000 left homeless. Lebanese President Michel Aoun warned that the death toll is likely to rise.

"It is time to grieve for our martyrs, wounded and missing," he told the country's national news agency.

As new details emerged, the government on Wednesday ordered the house arrest of port officials who knew about the thousands of tons of ammonium nitrate explosives stored at the port for six years without safety measures. Aoun said the officials would face "the harshest punishment" if they are found responsible.

Records show that a Russian-owned cargo ship ran into trouble and pulled into port in 2013. Abandoned, its deadly cargo was transferred to a port warehouse.

Small explosions thought to be from fireworks in storage were seen before the massive shock wave that swept through the capital, shattering the peace of a summer's afternoon. A smiling bride posing for pictures on her wedding day. The children watching the fire at the port burn from a window. The domestic worker who risked her own life to save a toddler.

At least one U.S. citizen was killed in the blast, and "several" more were injured, a State Department official confirmed Wednesday. The department said they are attempting to track down any other Americans who may have been injured in the catastrophic explosions.

Beirut's governor, Marwan Abboud, compared the destruction to the atomic bombings of Hiroshima and Nagasaki in World War II. "Never in my life have I seen destruction of such magnitude," he told local reporters.

Journalist Ghada Asharif said she was lucky she was at work. Her home was destroyed. "I think everybody is in immense shock," Asharif said. "I think beyond the physical damage, there's the mental sort of national trauma that everybody is processing."

There is much to process. In addition to the deaths, mass injuries and widespread destruction. The blast leveled the port and decimated its grain silos, in a country that was already facing an economic collapse long before the explosions.

Sophie Lewis contributed to this report.