EMBED >More News Videos Six remaining chemical containers at a flooded Crosby plant could explode at any moment.

EMBED >More News Videos RAW: Ted Oberg presses for answers about why more wasn't done sooner at the Arkema plant.

CROSBY, Texas (KTRK) -- The Arkema plant in Crosby has exploded, sending dark, black smoke into the air.In words most wouldn't expect to follow that sentence, that was expected to happen.Arkema officials acknowledged the fire, adding "we will likely see additional incidents."At least 18 people have been injured since the first fire earlier in the week. One of the injured complained of a burning sensation in the eyes and throat and was still feeling the effects, days later.The danger persists.A time line is hard to pin down as are answers to serious questions about how the company got here and what can be done next.Understanding that the plant site flooded is simple to do. The rain was bad all over and especially on the northeast side of town. Just eight miles from the Arkema plant, a rain gauge set an all-time rainfall record for the continental United States.But the record rainfall did not surprise meteorologists, like ABC13's Tim Heller, who had sounded the warning since at least Tuesday, Aug. 23, predicting "crazy amounts of rainfall."Those warnings continued all week.Flooding is not new to the plant site anyway. Neighbors say it happens all the time. The site sits in a floodplain. A company insider told ABC13 it led to a fire noted in state environmental violations records from 2006.An internal company timeline shows the plant shut down on Aug. 25. At that point, it had rained less than an inch there, according to the National Weather Service. Arkema sent nonessential personnel home on Aug. 26 when that area got nearly 26" of rain. The deluge came the next day when the area got nearly 27" of rain.The internal document suggests that when the flooding started and Arkema moved the temperature-sensitive chemicals into those refrigerated trucks, it was likely too late to drive them out. Had they moved them earlier, the outcome may have been different. But the company decided to leave it in place with two backup systems.They both failed."Clearly that wasn't enough," said Arkema safety expert Darryl Roberts. "Clearly, as we go forward we will do something different."That may help in the future. It doesn't help now.There is still no certainty on future fires and no clarity on just how big of an issue the fire could be.Plant officials said they expected the explosion and fire as chemicals began to heat up after the plant lost power during this week's flood. There are nine containers with 500,000 pounds of material inside. One of the containers already burned. Two ignited Friday.Friday's fire was the second fire and explosion after a much smaller one erupted Monday.As the water surrounds the plant into the weekend, there's no one there to monitor any spillage from the now destroyed trailer or any others and little word is coming from the company about exactly what chemicals are on site.One Safety Data Sheet on chemicals suspected of being there warns "to avoid releasing to the environment." Another warning says it's "harmful to aquatic life with long lasting effects."The plant's record with state and federal regulators isn't stellar either, something the plant's president acknowledged in a phone conference Friday."We're not perfect," said Arkema CEO Richard Rennard. "We're doing our very best and and will continue to work to get better."LISTEN TO THE FULL FRIDAY PHONE CONFERENCE WITH ARKEMA OFFICIALS